t _.... mm. b .afiuwmuumxia. ..d..a . £ a; filv. Ufl.narwn3srll .anwmfinéti mi 0151:.- .. £5.25!)- . a .5 t. . . {slant-id. ‘sl Hutu 5.0521: . .. , . 1... a «is. .. 3.3. acting". . 41 .1...» M. . . . ,f 5:. w V 7 ..\ 1a... . mm. “a“ .. {akfifi REE... x113: .- 1'3ng l l mummy l ZODq [IIEIIUF it, i I O‘u‘e Uni\ ’ersiiy This is to certify that the dissertation entitled COMPARISON OF NATIVE-ENGLISH AND NATIVE- KOREAN SPEAKING UNIVERSITY STUDENTS’ DISCOURSES ON INFINITY AND LIMIT presented by DONG-JOONG KIM has been accepted towards fulfillment of the requirements for the Ph.D. degree in Mathematics Education _a_.—.-.—--—-—.-.—.-._ _ .. imam» MCI/7% (/Major Professor’s Signatur 61/1309 Date ' MSU is an Affirmative Action/Equal Opportunity Employer — .-..-.—--------u—---.-—---.—.--.o--I--- -- —- - PLACE IN RETURN Box to remove this checkout from your record. TO AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE 5/08 KzlProj/Acc8PrelelRC/DateOue undd COMPARISON OF NATIVE-ENGLISH AND NATIVE—KOREAN SPEAKING UNIVERSITY STUDENTS’ DISCOURES ON INFINITY AND LIMIT By Dong-Joong Kim A DISSERTATION Submitted to Michigan State University in Partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Mathematics Education 2009 ABSTRACT COMPARISON OF NATIVE-ENGLISH AND N ATIVE—KOREAN SPEAKING UNIVERSITY STUDENTS’ DISCOURES ON INFINITY AND LIMIT By Dong-Joong Kim This study investigated and compared how native-English and native-Korean speaking university students, who received their education respectively in the US. and in Korea, thought about the concepts of infinity and limit. The primary motivation for this study was the discontinuity in Korean and the continuity in English between the non- mathematical and mathematical discourses on infinity and limit: non-mathematical uses of the mathematical words infinity and limit appear only in English. Based on the communicational approach to cognition, according to which mathematics is a kind of discourse, the characteristics of students’ discourse on the topics were identified. The participants’ discourse was scrutinized with an eye to the common characteristics as well as culture- and education-related differences. The setting for the study was a calculus class for university students in the US. and Korea. Methodology involved surveys and interviews. A total of 132 English speakers and 126 Korean speakers participated in the survey. Within each linguistically distinct group, twenty paired representatives were selected from the survey participants for follow-up interviews. The detailed discourse analyses of the interview transcripts generated preliminary hypotheses in the interviewees’ discourse on infinity and limit. Overall analyses of response patterns involved searching for frequencies and percentages of the survey participants’ responses and comparing the proportions of the two groups through chi-square analysis to confirm the emerging hypotheses. Data from both sources were used to elaborate and verify hypotheses. In order to attribute the specific source of differences in mathematical discourses of the two groups, students’ backgrounds which were likely to influence their mathematical discourses on infinity and limit were also investigated in this study. It is concluded from this study that the mathematical discourse of US. English speakers seemed to be growing continuously from their non-mathematical discourse, but there was no such continuity in the case of Korean speakers. The use of the mathematical nouns infinity and limit by English speakers was processual, just as it was in their non- mathematical, colloquial uses, whereas Korean speakers’ language was more formally mathematical and structural. This shows in developing their discourses on infinity and limit, English speakers seemed to build more on their previous everyday experience with discourses on infinity and limit, whereas Korean speakers had no choice but to rely on the structural discourse of mathematical textbooks. These differences in the use of the words infinity and limit between US. and Korean groups seemed to result in differences in endorsed narratives accepted by the students as true, routines they used in problem solving, and visual mediators they applied. In general, none of the mathematical discourses, either of English or Korean speakers, was fully compatible with the canonical mathematical discourse. The results of this study provide strong support for the conjecture that non- mathematical discourse shapes mathematical discourse of students — a fact that should be kept in mind in both the research on advanced mathematical concepts and teaching advanced mathematics. DEDICATION For my parents, my wife, Noah, and Ian iv ACKNOWLEDGMENTS I would like to acknowledge my thanks to the many people who made this study possible. Throughout this study and my doctoral work, the love, encouragement and support of my advisor, Dr. Joan Ferrini-Mundy left an indelible impression on my life. Dr. Anna Sfard, my co-advisor, patiently guided me throughout the writing process and continuously provided me insightful comments and an enthusiastic spirit. Thank you, Drs. Joan Ferrini-Mundy and Anna Sfard, for helping me to grow professionally. Next, I am grateful to all of my committee members, Drs. Glenda Lappan, Wellington Ow, and Woo- Hyung Whang, for their support and willingness to help me throughout this process. Thanks also to my colleague, Dr. Elizabeth Brown at Indiana State University, for her willingness to read and edit my dissertation. I particularly want to thank Dr. Woo- Hyung Whang, Dr. In-Chul Jung, and other graduate students at Michigan State University, Jung-Bun Park, Ga—young Ahn, and Joo-Young Park for helping with translations from Korean to English of the questionnaire and the interview transcripts. Of course, my family has also been with me through this process. Mom and Dad, I would like to thank you for loving and encouraging me. I want to give special thanks to my wife, Dr. Jeong-il Cho, for loving me. She and our sons, Noah and Ian, have been with me under both sad and happy circumstances. I could not have completed this study without them. Noah and Ian, I love you both very much. Lastly, I wish to thank Pastor Won and the church members in East Lansing for their warm caring and support. TABLE OF CONTENTS LIST OF TABLES ........................................................................................................... viii LIST OF FIGURES .......................................................................................................... xii CHAPTER I. INTRODUCTION AND RATIONAL .......................................................... 1 CHAPTER II. THEORETICAL BACKGROUND ............................................................. 4 Epistemology and History of the Notions of Infinity and Limit .................................. 4 Previous Research on Student Learning on Infinity and Limit .................................... 5 Previous Research on Use of Colloquial Language in Learning Mathematics ........... 6 Previous Research on Comparative Studies of Language ........................................... 7 Communicational Approach to the Study of Mathematics Learning ........................... 9 The Need for an Additional Approach ................................................................. 9 Communication Approach ................................................................................. 10 The Question to be Answered in This Research ........................................................ 13 The Pilot Study .......................................................................................................... 13 Summary .................................................................................................................... 15 CHAPTER III. DESIGN OF STUDY ............................................................................... 17 Research Questions .................................................................................................... 17 Overview of the Method ............................................................................................ 17 Method ....................................................................................................................... l8 Context ............................................................................................................... 18 Participants ......................................................................................................... 25 Data .................................................................................................................... 26 Analysis ............................................................................................................. 38 CHAPTER IV. ANALYSIS AND FINDINGS .................................................................. 41 Background Data about the Students and their Past and Present Mathematical Learning ..................................................................................................................... 41 Students' Background ......................................................................................... 42 Students' Current Mathematics Learning ........................................................... 50 Attitudes toward Mathematics ........................................................................... 6O Comparability of the E-group and K-group ....................................................... 62 Students’ Discourse about Infinity and Limit ............................................................. 64 Discourse on Infinity .......................................................................................... 65 Discourse on Limit ............................................................................................. 98 CHAPTER V. SUMMARY, DISCUSSION, AND CONCLUSIONS ............................. 138 Summary of Findings ............................................................................................... 139 Research Question 1 ........................................................................................ 139 Research Question 2 ........................................................................................ 140 Research Question 3 ........................................................................................ 144 vi Discussion of Findings ............................................................................................. 151 Reasons for Differences in Mathematical Discourse on Infinity and Limit ....151 Generalizabiltiy ........................................................................................................ 157 Limitations of the Study ........................................................................................... 157 Further Questions ..................................................................................................... 159 Conclusions .............................................................................................................. 160 Theoretical Conclusions ................................................................................... 160 Practical Implications ....................................................................................... 162 APPENDIX A: The Pilot Study Questionnaire ................................................................ 165 APPENDIX B: Others ..................................................................................................... 168 APPENDIX C: Questionnaire .......................................................................................... 179 REFERENCES ................................................................................................................ 204 Vii LIST OF TABLES Table 3.1. Colloquial and mathematical uses of infinity and limit in English and Korean18 Table 3.2. Summary of the characteristics of MSU and KU ............................................. 21 Table 3.3. Percentages of Students’ responses to the question about high school textbooks ............................................................................................................................................ 21 Table 3.4. The course and content categories for limit ...................................................... 38 Table 3.5. Theoretical components assessed by each item ................................................ 40 Table 4.1. Demographic characteristics of the survey participants ................................... 43 Table 4.2. Summary of textbooks used in high school ...................................................... 44 Table 4.3. Summary of course series taken in high school ................................................ 44 Table 4.4. Summary of the participants’ recollection of experiences with infinity and limit ............................................................................................................................................ 21 Table 4.5. Grades in which students recalled first hearing the words infinity and limit ....47 Table 4.6. Percentages of students reporting having studied specific topics related to infinity in high school and the results of chi-square .......................................................... 48 Table 4.7. Percentages of students reporting having studied specific topics related to limit in high school and the results of chi-square ....................................................................... 48 Table 4.8. Percentages of students’ responses to the classroom environment items and the chi-square results ............................................................................................................... 52 Table 4.9. Percentage distributions of extra lessons and homework and the chi-square results ................................................................................................................................. 53 Table 4.10. Percentages of Students’ responses to the out-of—school activity items and the chi-square results ............................................................................................................... 55 Table 4.11. Mean (M) and SD results to the extent of time spent out-of—school ............... 56 viii Table 4.12. Summary of students’ descriptions of how to study calculus ......................... 57 Table 4.13. Students’ views of themselves as mathematics learners and the t-test results of the comparison of percentage of the Korean and E-speakers’ responses .......................... 61 Table 4.14. The role of mathematics in Students’ lives and the t-test results of the comparison of percentage of the Korean and E-speakers’ responses ................................ 62 Table 4.15. Summary of interview responses using the word infinite in items I and IX ...66 Table 4.16. Summary of interview responses using the word infinity in items I and IX ...67 Table 4.17. Distribution of the contexts of use of the word infinite and the chi-square results of the comparison of difference between the E-group and K-group ...................... 68 Table 4.18. Distribution of types of entities described with the word infinite ................... 68 Table 4.19. Distribution of the use of the word infinitely as a descriptor of many ............ 69 Table 4.20. Distribution of sentences not using the noun infinity ...................................... 70 Table 4.21. Distribution of the use of infinity as process ................................................... 70 Table 4.22. Distribution of endorsed narratives for comparing pairs of two 'sets in item H ............................................................................................................................................ 21 Table 4.23. Comparisons between fingers and toes in item II-a ........................................ 73 Table 4.24. Comparisons between odd and even numbers in item II-b ............................. 74 Table 4.25. Comparisons between odd numbers and integers in item II-c ........................ 75 Table 4.26. Distribution of phrase-driven and structural uses of infinity .......................... 76 Table 4.27. Distribution of routines in comparison tasks in item H .................................. 79 Table 4.28. Distribution of contradictory answers in items II-b and H-c .......................... 80 Table 4.29. Distribution of endorsed narratives in item II-c and item 111 ......................... 83 Table 4.30. Distribution of the word use of bigger ............................................................ 83 ix Table 4.31. Distribution of routines in comparison tasks in items II-c and III .................. 84 Table 4.32. Comparisons between even numbers and integers in item 111 ........................ 86 Table 4.33. Distribution of processual and structural uses of infinity ............................... 87 Table 4.34. Distribution of routines in comparison tasks in items 1H and IV .................... 88 Table 4.35. Distribution of the word use of larger in item IV ........................................... 89 Table 4.36. Comparisons between the two infinite sets A and B in item IV ..................... 90 Table 4.37. Distribution of processual and structural uses of infinity ............................... 91 Table 4.38. Responses to the question in item VIII-a ........................................................ 92 Table 4.39. Use of infinity in a sequence ........................................................................... 93 Table 4.40. Salient properties of E-speakers’ and K-speakers’ discourse on infinity ........ 96 Table 4.41. Summary of interview responses using the word limited in items I and IX ...99 Table 4.42. Summary of interview responses using the word limit in items I and IX ..... 100 Table 4.43. Distribution of the contexts of use of the words limited and the chi-square results of the comparison of difference between the E-group and K-group .................... 101 Table 4.44. Distribution of the use of the word limiteda,” as an upper-bounded proceslel Table 4.45. Distribution of the use of limitedKMam as extreme ........................................ 101 Table 4.46. Distribution of the contexts of use of the word limit and the chi-square results of the comparison of difference between the E-group and K-group ................................ 102 Table 4.47. Distribution of the use of the word limitCou .................................................. 103 Table 4.48. Distribution of the use of and limitKMa,’I as extremity .................................. 103 Table 4.49. The table shown in item V in the questionnaire ............................................ 104 Table 4.50. Distribution of endorsed narratives in item V .............................................. 104 Table 4.51. Responses to the question about the limit of an infinite sequence in item V106 Table 4.52. Distribution of the use of the limit of the infinite sequence .......................... 107 Table 4.53. Distribution of the use of two columns ......................................................... 107 Table 4.54. Distribution of routines in item V ................................................................. 109 Table 4.55. Distribution of endorsed narratives in items VI-a and VI-b ......................... 111 Table 4.56. Distribution of endorsed narratives in item V—c ........................................... 111 Table 4.57. Responses to the question about the limit of l in item VI-a ...................... 114 x Table 4.58. Responses to the question about the limit of Ti in item VI-b ................. 115 + x x2 Table 4.59. Responses to the question about the limit of 2 in item VI-c .............. 116 (1+ x) Table 4.60. Distribution of the use of the contexts in item VI ......................................... 117 Table 4.61. Distribution of routines in item V-a .............................................................. 120 Table 4.62. Distribution of routines in items VI-b and VI-c ............................................ 120 Table 4.63. Distribution of endorsed narratives in item VII ........................................... 124 Table 4.64. Responses to the question about the limit of regular polygons inscribed in a circle in item VH .............................................................................................................. 126 Table 4.65. Distribution of the use of the limit in the sequence of regular polygons ...... 127 Table 4.66. Distribution of routines in item VII .............................................................. 128 Table 4.67. Responses to the question in item VIII-b ...................................................... 131 Table 4.68. Distribution of the use of the limit P in a sequence ...................................... 132 Table 4.69. Salient properties of E-speakers’ and K-speakers’ discourse on limit .......... 134 xi LIST OF FIGURES Figure 1. Questions 1 through 7 from the background questionnaire ................................ 28 Figure 2. Questions 10 and 14 from the background questionnaire .................................. 29 Figure 3. The questions in the first item ............................................................................ 31 Figure 4. The questions in the second, third, and fourth items .......................................... 32 Figure 5: The questions in the fifth and sixth items ........................................................... 33 Figure 6: The questions in the seventh and eighth items ................................................... 34 Figure 7. Geometric representations provided in item VII .............................................. 124 xii CHAPTER I INTRODUCTION AND RATIONALE The purpose of this study is to investigate and compare how native-English and native—Korean speaking university students who received their education in the US. and in Korea, think about the concepts of infinity and limit. Based on the communicational approach to cognition, according to which mathematics is a kind of discourse (Sfard, 1998), Sfard’s frame for analyzing discourse is used to investigate students’ thinking about infinity and limit. Infinity is the conceptual basis for mathematical topics such as the number line and infinite decimals. Since the 19’h century the concept of limit has been essential to mathematical analysis. As known to teachers and as confirmed by researchers, most students have considerable difficulty with the notions of infinity and limit. Since the mid 19603 large-scale international comparative studies have been carried out to investigate student learning. These studies show that East Asian students, such as those in China, Japan, and Korea, outperform their US. counterparts in mathematics. However, these large-scale studies do not examine the reasons for this disparity in the results. Nor do they provide a satisfactory method of helping students overcome their leaming difficulties (Wang and Lin, 2005). In order to have a better understanding of why and how East Asian students outperform US. students, more grounded qualitative studies are needed. This study is an attempt to investigate students’ thinking about infinity and limit using a different conceptual framework of learning — not from a cognitivist, acquisitionist perspective, but rather using a participationist view with attention to socio-cultural contexts. The first basic assumption in this study is derived from the communicational approach to cognition. The communicational framework conceives of thinking as communication with oneself, of mathematics as a form of discourse, and of learning mathematics as a change in ways of communicating (Sfard, 2000). The second assumption is that when students are thinking, meta-discursive rules guide them to do it in a certain patterned way. Throughout discursive activity, routines as repetitive patterns are implemented with other features of mathematical discourses (uses of words, visual mediators, and endorsed narratives). The third important assumption is that when students come to the classroom to learn mathematical concepts they already have a certain amount of knowledge about these concepts that come from daily experience. This is based on the view that mathematical learning involves thinking with and through informal everyday language, generalizing everyday concepts associated with mathematical words, and abstracting those concepts with schooling. This study attempts to answer the questions raised by these assumptions. One specific question about learning mathematics as changing mathematical discourse is: What are the leading characteristics of non-mathematical and mathematical uses of infinity and limit both between and within each of two linguistically distinct groups of university students? Because mathematical discourse may have culture-specific characters, two critical questions derived from the third assumption include: “What are the similarities and differences between native-English and native-Korean speakers in their former mathematics education and curricular experience with the words infinity and limit?” and “What are the similarities and differences between native-English and native— Korean speakers in their non-mathematical and mathematical discourses on infinity and limit?” This study may be of significance to the larger field of mathematics education for several reasons. First, discourse analysis may lead to methods for helping students overcome their difficulties with the central concepts of infinity and limit, with important implications for teacher education and K-16 curriculum. It may provide insight into the role of language in mathematical thinking in general and into the basis of the common phenomenon known as misconceptions in particular. Second, such investigations will address some previously unanswered questions such as “What is the role of the knowledge that students bring to the classroom from out-of-school settings?” and “Why do people have different uses for what they learned in different contexts?” Third, the communicational approach may prove fruitful for investigating advanced mathematical thinking in other areas. Findings of this study regarding infinity and limit may enlighten us about the ways that students and teachers deal with other notions such as continuity, differentiability, and integration in calculus. Finally, applying this approach to culturally diverse groups of students may shed additional light on an issue of great importance, vigorously pursued currently by researchers, namely how culture affects student learning in mathematics. CHAPTER II THEORETICAL BACKGROUND This chapter sets forth epistemology and history of the infinity and limit concepts to describe the genesis and evolution of both of the notions, as well as the interdependence between them. This chapter also includes a review of previous research on learning infinity and limit. In addition, literature reviews on two topics, colloquial use of language in learning mathematics and comparative studies of language in learning mathematics, are presented. Next, the communication approach to mathematical learning that guides this study and contributes to the research design is discussed. Finally, my pre-dissertation research as a pilot study is summarized. Epistemology and Histogy of the Notions of Infinity and Limit The histories of the mathematical concepts of infinity and limit have been interwoven since their beginning. The story of infinity begins with the ancient Greeks. For the Greeks, infinity did not exist in actuality, but rather as a potential construct. Although there was the notion of bounded processes, there was no concept of limit as a concrete bounding entity. In the Middle Ages, Christianity came to value infinity as a divine property. With the developments of astronomy and dynamics in the 16’h century, there was an urgent need to find methods for calculating the area, volume, and length of a curved figure. In the 17”” century, to find the areas of fan-shaped figures and the volumes of solids such as apples, Kepler used infinitesimal methods (Boyer, 1949). Throughout the 18’“ century, calculus lacked firm conceptual foundations. At the end of the 18’” century, mathematicians became acutely aware of inconsistencies which plagued the theory of infinitesimal magnitudes. Today’s notion of limit emerged gradually in the 19th century as a result of attempts to remedy the uncertainties existing within mathematical analysis at that time. Cauchy and Weierstrass were pioneers of the movement toward a rigorous calculus. At this time, limit turned into an arithmetical rather than geometrical concept, as it was before, in the context of infinitesimals. Infinity was now actual rather than potential. In order to complete Weierstrass’ foundations of arithmetic, Dedekind and Cantor developed the theory of the infinite set. Previous Research on Student Learning on Infinity and Limit Various aspects of the learning about infinity and limit have been investigated over the last few decades. Anchoring their research in the analysis of the mathematical structure of the notions, Cottrill et a1. (1996) report that there are two reasons for student difficulties with limits. One reason is the need to mentally coordinate two processes: x —-> a, and f (x) —-> L. The other is the need for a good understanding of quantification related to e and 6. Borasi (1985) suggests several alternative rules about how to compare infinities based on students’ intuitive notions (within this tradition, see also Cornu, 1992; Tall, 1992). Other research has focused on misconceptions and cognitive obstacles related to infinity and limit. Fischbein, Tirosh, and Hess (1979) and Tall (1992) emphasized the role of intuition. One source of difficulty with the notion of infinity is the belief that a part must be smaller than the whole. Other researchers (Comu, 1992; Davis and Vinner, 1986) stress the influence of language. Students may have had many life experiences with boundaries, speed limits, minimum wages, etc. that involved the word “limit”. These everyday linguistic uses interfere with students’ mathematical understandings (Davis and Vinner, 1986). Przenioslo (2004) focuses on the key elements of Students’ concept images of the limits of functions. Still others have focused on informal models that act as cognitive obstacles (Fischbein, 2001; Williams, 2001). According to Williams, informal models based on the notion of actual infinity are a primary cognitive obstacle to students’ learning. Finally, some researchers address students’ difficulties through the lens of the theory of actions, processes, objects, and schemas (APOS; see Weller, Brown, Dubinsky, McDonald, and Stenger, 2004). Weller et al. discuss the cognitive mechanisms of interiorization, encapsulation, and thematization that are used to build and connect actions, processes, objects, and schemas. Previous Research on Use of Collguial Language in Learning Mathematics To investigate the use of language in learning mathematics, many researchers have examined several mathematical topics on the basis of three different approaches to everyday language. One of the approaches focuses on the meanings of everyday language and their effects on learning mathematics. Some research has shown that Students’ misconceptions are influenced by the meanings of everyday language in learning mathematics (Comu, 1992; Davis and Vinner, 1986; Pimm, 1984; Raiker, 2002; Schwarzenberger and Tall, 1978). Students continue to rely on their misconceptions stemming from everyday language because even though the everyday and mathematical meanings of words are similar, their different uses in mathematics classrooms are significant. In the same vein, other research addresses the use of language in bilingual or multilingual contexts (Clarkson, 1992; Gutierrez, 2002; Moschkovich, 1996; Setati, 2002). Bilingual students employ not only different uses of concepts, but also different perspectives on mathematical tasks. Another approach stresses the effects of the structures of everyday language on mathematical learning (Bintz and Moore, 2002; Cotter, 2000; Leung, 2005). For instance, the difficulty of the patterns for counting in the English language (e.g., “l-ten 3” in the Asian number pattern instead of thirteen in English) interferes with American students’ mathematical understandings of counting. Most previous research on the role of colloquial language in learning mathematics has been grounded in the meanings and structures of everyday language. Comparative] y, the approach used in this dissertation views mathematical learning as a discursive activity that employs mathematical objects including language as well as meta-level factors. Previous research based on the discursive approach to mathematical learning is not extensive (Anderson et al., 2004, Barwell, 2003; Ben-Yehuda et al., 2005). Based on the communicational framework, Ben-Yehuda and colleagues (2005) characterize the arithmetic discourses of two 18-year old girls with learning difficulties in terms of four features of mathematical discourse including routines as a meta-level factor. They claim that the use of colloquial arithmetic discourse in learning literate mathematical discourse is important. Previous Research on Comparative Studies of Langgage in Learning Mathematics There is a limited number of comparative studies on language in learning mathematics. Song and Ginsburg (1988) are among the earliest to conduct a comparative study between two languages in learning mathematics. They investigate how far American and Korean preschool children can count. There are two different systems of number words in the Korean language. One is the everyday system, which is irregular like the English language number system, and the other is the academic system, which is regular like the Chinese number system. Song and Ginsburg report that the four year-old Korean had an initial difficulty with both counting systems (everyday and academic systems) and their ability to count was less developed than that of the American counterparts. However, after learning the academic system of counting, the six year-old Koreans attain a higher level of performance in counting than their US. counterparts. It is concluded that the everyday number system provides the Korean a cognitive advantage for understanding a base-ten structure at school (within the comparison of counting systems, see also Fuson and Kwon, 1992; Miura, Okamoto, Kim, Chang, Steere, and Fayol, 1994). Few comparative studies focusing on the Chinese language have in mathematics been conducted (Han and Ginsburg, 2001; Li and Nuttall, 2001). One representative of experimental studies is a work by Han and Ginsburg (2001). They ask 48 judges to rate the clarity of 71 mathematical words in Chinese, English, and “Chinglish” which is an English equivalent to the Chinese words. Chinese mathematical words are rated higher in clarity than English mathematical words. Chinglish mathematical words also tend to be rated higher in clarity than English words. After that, a mathematics test including 71 mathematical words is given to three groups of Chinese-American eighth graders: 33 Chinese-only speakers, 29 bilingual speakers of Chinese and English, and 20 English- only speakers. The result of the test reveals that the Chinese-only speakers and the Chinese-English bilinguals outperform the English-only speakers. Therefore, Han and Ginsburg hypothesize that the clarity of Chinese mathematics language may contribute to the better performance of the groups of the Chinese-only and bilingual speakers. Communicational Approach to the Study of Mathematical Learning The Need for an Additional Approach to Study the Learning of Infinity and limit In spite of the mutual interdependence of the concepts of infinity and limit in the history of mathematics, there has been little research to examine Students’ understandings of and difficulties with both concepts simultaneously. For a better understanding of the notions of infinity and limit and of their relationships, more research about student learning on the concepts together is needed. As influenced by the work of Piaget, mathematical learning has been considered as a process of active cognitive acquisition. Most previous research on the learning of infinity and limit has been grounded in the acquisitionist framework. The acquisitionist tenets have brought important insights (e. g., cognitive structures of infinity and limit, Students’ misconceptions, and the hierarchical relationships between categories in these concepts) into mathematical learning and teaching on the basis of the three different cognitive approaches to the learning of infinity and limit. The acquisitionist research, however, has not led to satisfactory solutions to account for inter-personal and cross-situational differences and the source of human development (Sfard, 2006). They also underestimate not only the inherently social nature of student thinking, but also the role of discourse and communication in learning and in other intellectual activities. Most previous research on the use of colloquial language in learning mathematics has not moved beyond attempts to characterize the meanings and structures of everyday language and their impact on mathematical learning. Some researchers in the discursive view on mathematics learning reported mathematical object-level and meta-level factors (such as patterns of attention, and routines) in mathematical discourse. However, previous discursive research focused only on primary and secondary school mathematics. Previous comparative studies emphasizing the importance of language in learning mathematics have also been conducted mainly with primary and secondary mathematics. Thus, there has been little comparative research on the role of colloquial discourse in learning mathematics at the post-secondary level. More comparative studies on advanced mathematical topics using the discursive approach to mathematical learning are warranted for a better understanding of how students think in general. Communicational Approach While Piaget focuses on the individual development, Vygotsky concentrates on the social activity of the mind as a starting point. From Vygotsky’s point of view, speech for communicating with others comes before internal speech in children’s internalization of higher mental processes. The claim is vividly made in the following excerpt: Every function in the child’s cultural development appears twice: first on the social level, and later, on the individual level; first between people (inter-psychological), and then inside the child (intra-psychological). (Vygotsky, 1978, p.57) Thinking arises from an individualized version of interpersonal communication because of the inherently social nature of human activities. Higher mental processes are developed through the procedures of internalization from public speech to inner private speech, and are tightly related to tool-mediated activity (Vygotsky, 1986). For instance, symbols and mathematical language are important tools in mathematics. The properties of such tools are inseparable from the cognitive processes of the uses of the tools (Rogoff, 1990). Thus, thought and language are inseparable; so are thought and symbols. Thought must be transferred through meanings and only then through words as a tool. 10 According to Vygotsky (1986, p.256), “the word is a direct expression of the historical nature of human consciousness”. In other words, consciousness can be investigated as it is expressed in words. In the communication approach, thinking is a special form of communication which is the process of internalization from public speech to inner private speech. Because thinking arises from an individualized version of interpersonal communication, it is simply communication with oneself and thus learning is a change in ways of communicating (Ben-Yehuda et al., 2005). In particular, learning mathematics is seen as becoming more skillful and articulate in mathematical discourse (Sfard, 2001a). The word discourse signifies any type of communicative activities, whether with others or with oneself, whether verbal or not, whether synchronic (like in a face-to face conversation) or asynchronous (like in an exchange of emails or reading a book) (Sfard and Lavie, 2005). A discourse is regarded as mathematical if it deals with mathematical objects, such as infinity and limits (Ben-Yehuda et al., 2005). When we use mathematical words such as limit in an everyday context, we call it a colloquial use in colloquial discourse. Thus, to discover the mechanisms of mathematical thinking, the discourses that students use in both the contexts of everyday life and mathematics are important because they can be used not only to express thinking processes, but to reveal what students already know. Whenever mathematical discourses are being analyzed, compared, and watched for changes over time, four distinctive features are often considered: words and their use, mediators and their use, endorsed narratives, and discursive routines (Ben-Yehuda et al., 11 2005; Sfard, 2001b; Sfard and Lavie, 2005). In this study, all four features are considered to identify characteristics of mathematical discourses. Uses of words are the ways the participants use keywords of colloquial and mathematical discourse regarding infinity and limit. Word uses are important as a feature of colloquial and mathematical discourses because they can reveal how students understand those words. For instance, how students use their mathematical words can be assessed by the degree of objectification. The degree of objectification will be assessed according to the frequency with which students speak about infinity and limit, as if these words referred to self-sustained, discourse-independent objects. The degree of objectification can indicate, among others, how students make the use of the words infinity and limit similar to the discourse on material objects such as apples or atoms. Discursive routines are the patterns of repetitive actions in students’ discourses. For example, we can observe such patterns in the mathematical discourses of comparing, counting, and defining. When students mention mathematical use of keywords, certain discursive routines can also be detected. Therefore, discursive routines are the central concept in discourse analysis. Routines are a set of meta-rules. When we consider meta- rules, two important aspects need to be emphasized. One of them is when the routine procedure is used and the other is how it is implemented. When refers to the cues for beginning discursive routines. How refers to the kinds of patterns which exist in discursive routines. Endorsed narratives are propositions that students accept as true. A narrative endorsed by an interviewee does not have to be a quotation from the interviewee. It may be an interpretation of assumptions that tacitly guides him or her. For instance, the 12 expression “Limit is something ...” can be inferred from statements actually made by students. Thus, through discursive activity, students can produce endorsed narratives. Visual mediators are means that the participants use for their communication activity. While colloquial discourses are communicated with the help of concrete objects or individual images, mathematical discourses are mediated by informal and formal symbols. For example, to identify infinity in mathematical discourse, students can use and refer to such mediators as an infinity symbol (00), three dots (. . .), and an “eight sideways” (oo) in multiple ways. The uestion to be Answered in This Research American and Korean students differ considerably in their mathematics achievements, as shown in large-scale international comparative studies. Difference in language is one of many cultural differences between these two groups that are relevant to understanding the relationship between mathematics learning and culture. Therefore, the difference in relations between colloquial and mathematical discourses on infinity and limit in Korean-speaking and English-speaking students are explored in this study. The Pilot Study A pilot study was conducted in preparation for this study (see Kim, 2006). I interviewed four American and four Korean students in fall 2004. Each ethnically distinct group included one elementary school student, one middle school student, one high school student, and one undergraduate. The participants within the same grade level (elementary, middle and high schools, and college) were selected based on the criteria of the same age, grade, and educational institution. Their discourse on infinity and limit was scrutinized with an eye to common characteristics as well as culture-, age-, and 13 education-related differences. Because the interviews were conducted in English, the four Korean students who were selected had been living in the United States and attending US schools for more than three years. The interview questionnaire consisted of 29 questions in eight categories. The first two categories aimed at scrutinizing Students’ colloquial discourses on infinity and limit, whereas the remaining six categories were targeted at investigating Students’ mathematical discourses on the topics (see Appendix A for the full questionnaire). The interviews were audio- and video-taped and then transcribed in their entirety for further analysis. Data were analyzed so as to identify and describe the four distinctive features of the respondents’ discourses: word use, discursive routines, mediators, and endorsed narratives. One significant finding was that the Korean and American students used infinite and infinity in different ways, and used limited and limit in similar ways in both colloquial and mathematical discourses. There were few noticeable differences between the American and Korean groups in the colloquial and mathematical discourses on infinite and infinity (e. g., the element-based approach to the word infinity in the Korean group versus the set-based approach in the American group). However, there was no systematic difference between the American and Korean students in their discourses on limited and limit. Another important finding was that there were no significant systematic differences with age in the colloquial and mathematical discourses on infinity. In contrast, some age- related characteristics of the Students’ word use and endorsed narratives on limit were found in the study (e. g., objectified word use as a particular number and the endorsement of limit as an unreachable object for the older students). 14 Although the sample size of the pilot study was too small to allow for generalization, the findings served as a basis for the hypotheses that were tested in this study. According to the results of the pilot study, colloquial discourse seems to have an impact on mathematical discourse as evidenced by certain clear differences between the mathematical discourse on infinity of the American and the Korean students. These differences can be ascribed to the fact that only in English do the mathematical words infinity and infinite (as well as set and element) appear in colloquial discourse. The absence of systematic differences between the two ethnic groups in their discourses on limited and limit might be ascribed to the fact that unlike the word infinity, the words limit and limited are quite commonly used in English colloquial discourses. Due to the fact that all the Korean students had been living in the United States and attending US school for more than three years, they may have been influenced by the colloquial and mathematical English discourses on infinity and limit. Therefore, in the present study, native Korean students, who have not experienced English colloquial and literate discourses on infinity and limit, will be chosen and interviewed about their discourses on infinity and limit in Korean. Stunner! The interconnectedness between infinity and limit in the history of mathematics justifies this study’s focus on both infinity and limit simultaneously. Because of the inherently social nature of student thinking, previous cognitive approaches to the learning difficulties of infinity and limit provide justification for the need for discourse analysis as a research methodology, with the promise of answering some previously unanswered questions within the traditional cognitive framework. Literature reviews on the use of 15 colloquial language and comparative studies of language in learning mathematics justify the need for comparative studies of language on learning advanced mathematics at the post-secondary level to better understand how students think in general. As noted earlier, communication is of principal importance in learning mathematics as a tool-mediated activity. These different perspectives as well as the pilot study laid the groundwork for the design of this study. 16 CHAPTER III DESIGN OF STUDY This study investigated how native-English and native-Korean speaking university students thought about the concepts of infinity and limit and compared their colloquial and mathematical discourses. The method chosen to fulfill this purpose was the communicational approach to cognition, according to which mathematics is a kind of discourse. This chapter describes the research questions and method. In addition, connections are drawn between the pilot study and certain methodological choices for this study. Research Questions The purpose of this study, to characterize how students think about infinity and limit, led to the following research questions: 0 What are the relationships between colloquial and mathematical uses of the English words infinity and limit? What are the relationships between colloquial and mathematical uses of the corresponding Korean words? 0 What are the similarities and differences between native-English and native-Korean speakers in their previous mathematics education experiences, their learning habits and their curricular experience with the words infinity and limit? 0 What are the similarities and differences between non-mathematical and mathematical discourses on infinity and limit of native-English and native-Korean speakers? Overview of the Method Two groups of university students (native—English and native-Korean speakers) participated in the study. The comparisons of these two groups were based on analyses of Students’ responses to a survey questionnaire and discourse analyses of paired interviews. After collecting the survey data, I first analyzed and categorized 132 English-speaking and 126 Korean-speaking university Students’ written responses to the survey within each 17 group, and chose their representatives from each group for the interview study. Twenty representatives in each group were interviewed in pairs, and discourse analyses on those interview data was conducted on the basis of the communicational framework. Finally, the written responses to mathematics problems on the survey were reanalyzed to make conjectures about the generality of characteristics observed in interviews. Method Context Sites The two sites, the United States and Korea, were chosen to investigate the three research questions (see Appendix B for an overview of the educational systems at the two sites). The specific reason for the selection of native-English and native-Korean speakers is the discontinuity in Korean and the continuity in English between the colloquial and mathematical discourses on infinity and limit. For the sake of the clarity in the following discussion, let us denote the colloquial and mathematical words for infinity and limit as specified in Table 3.1. Table 3.1 Colloquial and mathematical uses of infinity and limit in English and Korean English Korean Infinity Limit Infinity Limit InfinityKCon LimitkCon Colloquial InfinityECo" Limitgco" 391% (han-up-um), XIIEI (foe-hon), $¢(moo-soo),... 737‘“ (kyung-gae), InfinityKMath LimitKMam Mathematical InfinityEMath LimitEMath 'T'fl' (mu-halt) and 23* (gzlk-han) and $35" (mu-han—dae) 3331' (grik-han-gab) As can be seen from the table, the relation between the colloquial and mathematical words may now be presented as follows: InfinityECO" = InfinityEMath, whereas lnfinityKCo" at InfinityKMam l8 Limitgco” = LimitEMath, whereas LimitKCo“ ¢ LimitKMath Here, the equality symbol ‘=’ means that the words sound the same, not that their use is the same. InfmityKCou and LimitKCou signify the colloquial Korean words that can count as rough translations of InfinityECOH and LimitECOH, respectively. In English, the words infinity and limit appear in colloquial language and students are likely to be familiar with the terms before they encounter them in a formal mathematical context. Even young children are likely to be acquainted with expressions such as “infinity of problems” or “speed limit” that feature the same words which they will latter learn in its mathematical version. This is not the case for Korean children. The formal mathematical words for infinity and limit learned in school or university do not originate in colloquial discourse and the odds are that when the Korean children hear the Korean mathematical words for infinity and limit (InfinityKMmh and LimitKMath) for the first time, these words (the sounds) are completely new for them. Later, these words may make their way into their colloquial discourse, but this is irrelevant to this study. This difference between the Korean and American children’s linguistic experiences may be consequential. One can hypothesize that the early colloquial uses of the English words infinity and limit would influence, even possibly interfere with, the way students learn the formal mathematical use of these words. The pilot study brought an initial corroboration of this thesis when it showed, for example, that English speakers tend to use limitEMath the way mathematicians use the term “upper boundary” — the use that corresponds to the limitECo", as appearing in the colloquial expressions such as “speed limit” or “There is a limit to my patience.” Since there is no colloquial counterpart to the l9 limitKMath, it is reasonable to assume that there will be no such bias in the Korean students’ use of limitKMam1 (the use of the Korean mathematical counterpart of limitEMam). This linguistic hypothesis, if it is empirically corroborated, may explain at least some of the phenomena known as “misconceptions about infinity and limits” and, more generally, may shed light on the linguistic mechanisms that produce such phenomena. Thus, I tried to examine the possible impact of the discontinuity in Korean and the continuity in English on students’ mathematical thinking about infinity and limit. Research Sites A major university in the capital city of each site, Michigan and Korea, was selected for collection of data for this study. The Korean participants were selected from Korea University (KU). KU is located in Seoul, the capital city of Korea. KU is a private university with an enrollment of approximately 20,000 undergraduate and graduate students. Almost all the students in KU are Korean and international students comprise less than 3% of the total student population. At KU the Department of Mathematics offers only one calculus course. All freshmen whose major was science took the calculus course as a requirement. If students took calculus as one of the four elective courses in high school, they were expected to have some background in calculus. All calculus classes were taught by faculty and instructors in the Department of Mathematics. Each class size was under 60 students. Thomas’ Calculus (Thomas, 2005) was used as the textbook. The US. participants were selected from Michigan State University (MSU). MSU is located in East Lansing, three miles east of Michigan’s capitol in Lansing. MSU is a public university with approximately 45,000 undergraduate and graduate students. More 20 than 7% of the total student body is international students. There were more than 200 programs of study. MSU students came from all 83 counties in Michigan, all 50 states in the United States, and about 125 other countries’. All students whose major was natural science or engineering at MSU were required to take the calculus course MTH 132 as a requirement. If students had taken Pre-calculus as an elective course in high school, they might come to the university class with a background in infinity or limit. Faculty in the Department of Mathematics taught all MTH 132 classes. Each class size was under 35 students. In all MTH 132 calculus classes, the same Thomas’ calculus book was used. The characteristics of the two universities, MSU and KU, are summarized in Table 3.2. Table 3.2 Summary of the characteristics of MSU and KU MSU KU Location East Lansing, MI Seoul, Korea Number of students About 45,000 About 20,000 International students More than 7% of the total Less than 3% of the total . Students whose major is natural Students whose major is Calculus as a requrrement . . . . scrence or engineering scrence Each calculus class size Under 35 students Under 60 students Opportunities for Learning on Mathematical Infinity and Limit International comparative studies are meaningful and useful when they include a good alignment of achievement and opportunity to learn (see Wolfe, 1999 for positive correlations between achievement and opportunity profiles in the Second International Mathematics Study (SIMS) data and the International Assessment of Educational Progress (IAEP) data). In order to analyze students’ opportunities to learn infinity and limit, I used student responses about the textbooks they had used for learning infinity and limit as well as policy documents such as state and national standards. ' From the website, http://newsroom.msu.edu/snav/ I 84/page.htm 21 1) Opportunities of native-English speakers in the United States Characterizing students’ opportunity to learn about infinity and limit is complex in the United States because different curricula are used across schools and universities and this implies different experiences. However, Michigan’s Grade Level Content Expectations (GLCE) for grades K8 and High School Content Expectations (HSCE) in mathematics can be used to address students’ expected opportunity in general, in Michiganz. In order to describe what students should know and be able to do in mathematics, the Michigan’s GLCE addresses content standards categorized into the five strands at each grade level. The five strands consist of the following: 1) number and operations; 2) algebra; 3) measurement; 4) geometry; and 5) data and probability. The Michigan’s HSCE describes content standards in each course (Algebra 1, Algebra II, Geometry, Pre-calculus, and Statistics and Probability) on the basis of the four strands: l) quantitative literacy and logic; 2) algebra and functions; 3) geometry and trigonometry; and 4) statistics and probability. Michigan’s GLCE prescribe that non-terminating and non-repeating decimals are assessed at grade 8.3 In algebra 1, students are expected to learn about recursively defined functions, the behavior of a function as x approaches infinity, and asymptotic behaviour at infinity". In algebra 11, students are taught infinite geometric sequences and asymptotes 2 From the website, http://www.michigan.gov/mde/O,l607,7-l40-28753-—-,00.html 3 N. ME.08.03: Understand that in decimal form, rational numbers either terminate or eventually repeat, and that calculators truncate or round repeating decimals; locate rational numbers on the number line; know fraction forms of common repeating decimals, e.g., 0,]— = g; 05 = 1.. N. ME.0804: Understand that irrational numbers are those that cannot be expressed as the quotient of two integers, and cannot be represented by terminating or repeating decimals; approximate the position of familiar irrational numbers, e.g., J2 , J3 , 7r , on the number line. " A2.l.5 Recognize that fimctions may be defined recursively. Compute values of and graph simple recursively defined functions (e.g.,f(0) = 5, and fin) =f(n-l) + 2). 22 of rational functions’. If students take pre-calculus, they would be exposed to an opportunity to learn about the limit of a function as x approaches a number or infinity as well as infinite geometric series”. 2) Opportunities of native-Korean speakers in Korea Unlike in the United States, similar curricula are used across schools in Korea due to a centralized educational system. The mathematical word 51?." (mu-hon) for infinity without using the Chinese characters is first used in Korean schools to introduce the concept of infinite sets in the 7’h grade school curriculum (see Appendix B for the general development of the Korean language). As explained in the appendix, one thing to note is that Chinese characters show meanings and etymologies of words. In a 7’h grade textbook, a set is defined as a collection whose objects are clearly delineated. In the same textbook, an element is then described as a member of a set. After the introduction, Fri-15%| (mu-soo-hee) as a Korean colloquial word without using Chinese characters is used to define an infinite set. In the word mu-soo-hee, the meaning of the first character A2.I.6 Identify the zeros of a function and the intervals where the values of a function are positive or negative. Describe the behavior of a function as x approaches positive or negative infinity, given the symbolic and graphical representations. A2.3.l Identify a function as a member of a family of functions based on its symbolic or graphical representation. Recognize that different families of functions have different asymptotic behavior at infinity and describe these behaviors. ’ *L2.2.4 Compute sums of infinite geometric sequences. A2.9.2 Analyze graphs of simple rational functions (e.g., f (x) = 2 x + 1 ; g(x) = x ) and understand x—l x -4 the relationship between the zeros of the numerator and denominator and the function’s intercepts, asymptotes, and domain. 6 P1.7 Understand the concept of limit of a firnction as x approaches a number or infinity. Use the idea of limit to analyze a graph as it approaches an asymptote. Compute limits of simple functions (e.g., find the limit as x approaches 0 of fix) = l/x) informally. P8.4 Compute the sums of infinite geometric series. Understand and apply the convergence criterion for geometric series. 23 (mu) is none or nothing and the second character (soo) means number or count and the last character is a Korean suffix to make the word mu-soo as an adverb. Thus, an infinite set is introduced as a set which includes countlessly many elements using a Korean colloquial word mu-soo-hee. In the 10th grade mathematics curriculum, the other mathematical term $EI'EH (mu-han-a’ae) for infinity and its symbol (00) are introduced along with the concept of infinite sequence, as well as the new symbol (n—roo: as ‘n is getting bigger endlessly’). As in the case of infinity, there are also two Korean mathematical words for limit only written with Korean letters: 23 (gtik-han) and 3331 (guk-han-gab). The meaning of the first character (grik) is an extreme and the second character (han) means bound. The word at (gab) as a pure Korean word means value or amount. Thus the first mathematical word gtik-han for limit means “the utmost boundary.” According to a Korean dictionary, the Korean word gtik-han is equivalent to the word grik-han-gab. In the dictionary, the second mathematical word ngk-han-gab, used only in mathematics, is defined as “a value to which a function approaches, as independent variables approach to a number endlessly.” The word gzik-han for limit without using Chinese characters is first introduced to signify the limit of a sequence in the 10th grade mathematics curriculum. By the end of grade 12, students whose major will be science are expected to learn about the limit of a function, the limit of an infinite sequence, and sums of infinite series, whereas students who will study liberal arts at a university are not taught those concepts. 24 Opportunities of native-English and native-Korean speakers in the United States and Korea respectively for learning about infinity and limit are different. For native-English speakers in the US, the colloquial use of the English words infinity and limit precedes the mathematical use because native-English speakers first experience colloquial meanings of those words in everyday language and later they experience the mathematical meanings in high school. However, for native-Korean speakers in Korea, the mathematical words infinity and limit are first introduced at grades 7 and 10 respectively. Participants Students from several calculus classes at MSU and KU were recruited, yielding a sample of 132 English-speaking and 126 Korean-speaking university students for the study. Only MTH 132 calculus classes at MSU were included in this study because the content in MTH 132 was equivalent to that of the calculus course at KU in terms of using the same textbook (Thomas, 2005). All freshmen who majored in science were required to take the calculus course at KU, whereas most students who studied natural science or engineering took the MTH 132 calculus class at MSU. In Spring 2007, when the data were gathered, about 1740 students distributed in 29 sections were taking the calculus class at KU, whereas 533 students in 16 sections were registered for the MTH 132 class at MSU. Of those students, almost all the students at KU and about 70 percent of the total students at MSU were freshmen. Out of the undergraduate students who volunteered to participate, 20 students in each site were selected for paired interviews on the basis of their responses to the survey. The selection process was designed to maximize difference in degrees of exposure to and 25 experience with the concepts of infinity and limit throughout their formal education as well as to include students whose responses to the questions investigating colloquial and mathematical discourses on these concepts fell into various categories (see the section of procedures for collecting data about how to select 20 interviewees in detail). As the results of the pilot study (Kim, 2006) suggested, native Korean students who have not studied mathematics in English or any other language were chosen and interviewed in Korean regarding both their colloquial and literate discourses on infinity and limit. I selected interview subjects who had no experience in any language other than their native language in learning mathematics. Data from these native-Korean speakers might help explain the characteristics of their discourses described in the first research question. In a similar way, native-English speakers, who had not studied mathematics in Korean or any other language, were chosen and interviewed in English. M Questionnaire The primary instrument for data collection was a questionnaire (see Appendix C for the entire questionnaire, with both the English and Korean versions). The questionnaire consisted of two sections: Section I, Background; and Section II, Discourse. Section 1 aimed at examining students’ linguistic background, formal mathematics education, and curricular experience with the concepts of infinity and limit. Section II was composed of questions regarding creating sentences with infinity and limit and solving mathematical problems about these concepts. The discourse questionnaire (Section II) was piloted and subsequently revised. The questions from the discourse questionnaire were used for paired interviews to scrutinize students’ non-mathematical and mathematical discourses 26 on infinity and limit. Because the questionnaire was used in English and Korean, three mathematics educators and one linguist who were all Korean-English bilinguals were selected to evaluate the Korean translations of the questions into English. To address the first research question (about the leading characteristics of non- mathematical and mathematical discourses on infinity and limit), the problems for investigating non-mathematical and mathematical discourses in the discourse questionnaire were open-ended, providing the participants with an opportunity to freely express their thinking. Responses to open-ended questions permitted an investigation of students’ thought processes. Because of the nature of the questions focusing on specific features, only a subset of the four features (word use, endorsed narratives, visual mediators, and routines) in mathematical and non-mathematical discourses was dealt with within each question. Then, common characteristics (in terms of the four features) in discourse analysis on the interviews of ten pairs of native-Korean speakers were compared and contrasted to those of their native-English counterparts. To answer the second and third research questions (about the differences between native-English and native-Korean speakers in terms of their colloquial and mathematical discourses, formal mathematics education, and curricular experience), I hypothesized about relationships between characteristics of mathematical and colloquial discourses, formal mathematics education, and curricular experience with infinity and limit. Finally, I compared and contrasted the characteristics in these relationships between native-English and native-Korean speakers. The background questionnaire (Section I) included 21 questions mainly asking about Students’ linguistic background, formal education, and the textbooks that they used when 27 learning infinity and limit. Questions 1 and 2 ask about students’ year and native language. Question 5 is aimed at examining whether students have studied mathematics in any language other than their native language. Questions 6 through 9 ask in which grade and in which mathematics course students had first heard the mathematical words of infinity and limit. Questions 1 through 9 are shown in Figure 1. l.Year: D Freshman c1 Sophomore 13 Junior 0 Senior 2.Native Language: C] Korean Cl English D Other (Specify): 3. How often do you speak your native language at home? 0 Always Cl Almost always Cl Sometimes c1 Never 4. About how many books are there in your home? (Do not count magazines, newspapers, or your school books.) 0 None or very few (0-10 books) 0 Enough to fill one shelf (1 l-25 books) 0 Enough to fill one bookcase (26-100 books) 0 Enough to fill two bookcases (101-200 books) 0 Enough to fill three or more bookcases (more than 200 books) 5. Have you studied mathematics in any language other than your native language? nYw 0N0 If yes, specify the languages in which you learned mathematics: 6. Can you remember the first mathematics course in which you heard the word (mathematical) infinity? 0 Yes 0 No 7. If yes, specify in which grade(s) and in which course/class you heard the word (mathematical) infinity? Grade(s): Course: . 8. Can you remember the first mathematics course in which you heard the word (mathematical) limit? 0 Yes 0 No 9. If yes, specify in which grade(s) and in which course/class you heard the word (mathematical) limit? Grade(s): Course: Figure 1: Questions 1 through 7 from the background questionnaire Questions 10 through 14 were intended to investigate students’ different levels of exposure to and experience with infinity and limit in their formal education. Question 10 regarding the textbooks which students used in high school is included. A set of widely used textbooks was provided to the students. In question 11, the titles of sequences within each curriculum were used to investigate different levels of courses that students took in high school. Because students may take advanced mathematics courses other than the examples in question 11, question 12 was targeted to examine the most advanced mathematics course they took in high school. Questions 11 and 12 are included to investigate the topics in which students may have learned about infinity and limit in their 28 10.Please specify fi'om which high school textbook(s) series you studied among the examples below. If you used textbooks other than those in the exam les, lease check the box for Others. - 1 2) 3) ‘4 —fi rursokareo mmrmwcs namtnmtn (SEE‘HWH‘ : \~‘l " . . Viz-“jg , j r i .. {fife-i '- 0 Core-Plus Mathematics .. I _. . ‘ ’~ Interactive Mathematics SIMMS: Integrated Project (CPMP) Mathematics Connections program (IMP) ‘ ' ' ' 5 6) 7) Others V‘VIV ‘.. :1.- ‘ ". ' The University ofChicago Mathematics: Modeling ifi.‘::.-:+1'i 3U School Mathematics Our World Prentice Hall Project (UCSMP) ll.In high school, which course(s) in the series below did you take? Please check all the boxes that apply to you (under the textbook serieslou usej). CPMP Math Connections IMP Integrated Math U Course 1 U Algebra U Year 1 U Level 1 U Course 2 U Geometry U Year 2 U Level 2 U Course 3 U Advanced Algebra U Year 3 U Level 3 U Course4 U Year4 U Level4 UCSMP Moxl’ilrhgegfirmlzlorl d Prentice Hall Others U Transition Math U Course 1 U Pre-Algebra U Algebra U Course 2 U Algebra 1 U Geometry U Course 3 U Geometry U Advanced Algebra U Algebra 2 U Functions, Statistics ..findIEIEQE‘PIFFU'Y U Preealculus and Discrete Math 12.1n high school, what is the most advanced mathematics course you took other than those in #9? 13. Please check the box(es) next to topics which you have learned. Where and when did this learning occur? :1 Infinite processes 0 Infinite decimal fractions El Infinite sequence or series D The sum of infinite geometric series 0 Comparison of infinite sets C1 Countable and uncountable sets a Infinitely small or infinitesimal D Other topic (Describe): 14. Please check the box(es) next to topics which you have learned. Where and when did this leaming occur? 0 Limits to infinity CI The 8-5 (epsilon-delta) definition of limit c1 Limit of a sequence or series a Limit of a function numerically D Limit of a function geometrically u Limit and the definition of continuity 1:] Limit and the definition of the derivative :1 Other topic (Describe): Figure 2: Questions 10 and 14 from the background questionnaire 29 former education. Seven possible responses to each question are organized in a hierarchy and specified at several different levels with regard to the degrees of difficulties of infinity and limit. Questions 10 and 14 from the survey are shown in Figure 2. In addition to examining students’ former mathematics education and curricular experience with infinity and limit, the background questionnaire was used to investigate their crurent mathematics learning and attitudes toward mathematics. Questions 15 and 16 were intended to examine students’ view of themselves as mathematics learners and the role of mathematics in their lives respectively. Questions 17 through 21 were aimed at investigating students’ self-report on their learning of mathematics, out-of-school activities, extra lessons and homework (see Appendix C for details). The discourse questionnaire (Section 1]) consisted of 16 questions organized into eight items (see the section on data analysis for how the questions connected the four features in non-mathematical and mathematical discourses). Open-ended questions were employed so that the participants had an opportunity to freely express their thinking. Students’ responses to open-ended questions and the method of paired problem solving reduced interviewer’s effects and biases on interviewee’s responses. The first item aimed at scrutinizing students’ colloquial discourses on infinity and limit. The next seven items were designed to investigate students’ mathematical discourse on the topic. The distinction between non-mathematical and mathematical discourses in this study is important in this investigation of students’ thinking about infinity and limit. Students’ discourse on infinity and limit in response to items 11 through VIII was regarded as mathematical, not only because the questions framed the discourse as mathematical (and thus the student volunteers agreed to participate in this discourse), but also because the 30 participants did it by adjusting their colloquial discourse to the rules of school mathematical discourse. The descriptions of each questionnaire item are as follows. In the first item, students were asked to create a sentence for a given word to investigate their non-mathematical discourse on infinity and limit. In the Korean survey questionnaire, some representative words of infinitchO", infiniteKcOu, limithOn, and limitechOn were used. The questions in the first item are shown in Figure 3. I. (First Item) Create a sentence with the following word (term). 1. (Colloquial) Limited 2. (Colloquial) Limit 3. (Colloquial) Infinite 4. (Colloquial) Infinity Figure 3: The questions in the first item The remaining seven items were designed to investigate students’ mathematical discourses on infinity and limit. In the second item, students were asked to compare two sets (i.e., fingers and toes, odd numbers and even numbers, and odd numbers and integers). The aim of questions in the second item was to examine whether the routines for comparing finite sets were the same as the routines for comparing infinite sets. The infinite cardinalities in the second item are one of the most important concepts in infinity. Different degrees of infinity have been controversial in the history of mathematics. Cantor himself could not believe the different cardinalities between rational and real numbers when he first created them. Thus, questions involving comparisons of infinite sets have been one of the main methods for investigating student thinking about mathematical infinity (Borasi, 1985; F ischbein, Tirosh, and Hass, 1979; Tsamir and Dreyfus, 2002). In the third item, students also were asked to compare integers with even numbers. Unlike the second item, integers and even numbers were presented horizontally in order 31 to investigate students’ approaches to a contradiction. If students used the part-whole comparison in the second item, they may have reached a contradiction as they saw no consistency between part-whole and one-to-one correspondence comparisons in different representations of infinite sets. The third item was intended to raise a contradiction and promote student’s awareness of their contradictory conclusions when comparing infinite sets (Tsamir and Dreyfus, 2002). Thus, the third item could reveal meta-discursive rules in the ways of viewing a contradiction on the process of mathematical problem solving. The fourth item was targeted to examine students’ conceptions of the word larger in comparing infinite sets. Students may use different criteria in order to claim that one infinite set A is larger than the other infinite set B. As shown in the pilot study, one criterion is based on a competition (or race) between two running lists of elements within each infinite set. Another criterion is to compare two amounts of entire sets of elements. Thus, the fourth item could reveal criteria that students use for comparing two infinite sets. The questions in the second, third and fourth categories are shown in Figure 4. 11. (Second Item) 01’ which are there more? Please check one of the boxes. How do you know? 5. 1] Of your fingers or Cl Of your toes — because 6. El Of odd numbers or 1] Of even numbers — because 7. [:1 Of odd numbers or 1] Of integers — because 111. (Third Item) Which of the two sets A and B is bigger? How do you know? A = { 1, 2, 3, 4, 5, 6, 7, } B = { 2, 4, 6, 8, 10, 12, I4, } IV. (Fourth Item) A student claims that each of the two sets A and B is infinite, but A is larger than B. What can this mean? Figure 4: The questions in the second, third, and fourth items In the history of mathematics, one aspect of students’ learning difficulties with the notion of limit is the failure to link geometry with numbers (Cornu, 1991). In other words, the geometric interpretation in the concept of limit differs from the understanding of the notion of a numerical limit. Thus, both arithmetic and geometric contexts often have been used to investigate students’ difficulties regarding limit (Davis and Vinner; Monaghan, 32 1991, Szydlik, 2000). Specifically, the limit of a sequence in an arithmetic context and the limit of a function in a geometric context have been focused on in previous studies on limit. Thus, the intention of the fifth item was to investigate how students calculated the limit of a given sequence in arithmetic context. Graphical representations in the sixth item were utilized to examine students’ mathematical discourse on limit by using spatial principles in geometric context. Students might use different ways of mathematical discourse to approach different mathematical contexts. The questions in the fifth and sixth categories are shown in Figure 5. V. (Fifth Item) What do you think will hap en later in the columns of this table? x Vx+2 -5 x 1.0 0.099020 0.5 0.099505 0.1 0.099900 0.05 0.099950 0.01 0.099990 0.005 0.099995 0.00 1 0.099999 VI. (Sixth Item) What will happen to the curve in #8 as x approaches 0 from left or from right? What will happen to the curve in #9 and #10 when x goes to positive infinity? 2 2 8. l 9. x 10. x x l + x (1 +x)2 l l ’0‘ . ' 00 , l . o . r , O9 * v v v w v 7 v v v v . L I O " I l I. l l ' ‘9 ' e L l I l L .‘Q ‘ . , . b Figure 5: The questions in the fifth and sixth items In the seventh item, concrete geometric representations in limiting processes were used in the questions to examine different characteristics of students’ mathematical discourse on limit from the fifth and sixth categories. The questions in the seventh item could draw a result which explicitly explains how students think and their approach to the 33 limit in geometric progressing processes of regular polygons inscribed in a circle. The eighth item was intended to assess how students identity the limit of a sequence as either infinity or a number. Another purpose of the questions in the eighth item was to evaluate how students utilize the definition of limit in their minds in answering the questions. The questions in the seventh and eighth categories are shown below in Figure 6. VII. (Seventh Item) Examine the sequence of the square, the regular pentagon, hexagon (6 sides), heptagon (7 sides), ..., which is inscribed in the circle. ”’00 ...... What happens if you continue increasing the number of sides of a regular polygon inscribed in a circle? Explain your reasoning. VIII. (Eighth Item) - A student claims that a sequence a], a2, a3, goes to infinity. What does this mean? - A student claims that the number P is the limit of a sequence a}, a2, a3, What does this mean? Figure 6: The questions in the seventh and eighth items Unlike the English questionnaire, a ninth item was considered in the Korean questionnaire. With the Korean mathematical words of infinity and limit, the same question asked in the first item was used in the ninth item of the Korean questionnaire to thoroughly investigate Korean students’ discourse. In summary, the discourse questionnaire included a total of 16 questions in eight categories to investigate students’ colloquial discourse on infinity and limit and their mathematical discourse about these concepts in the different mathematical contexts. Procedures for Collecting Data During data collection, two main types of data were collected: students’ responses to the questionnaire and interviews with pairs of students solving the same tasks in the discourse questionnaire. First, I contacted instructors (e. g., teaching assistants or professors) who taught calculus classes at MSU and KU to ask about their willingness to 34 allow me to collect data in their classrooms. After obtaining approvals from the instructors, all the students in each identified classroom were asked during their classes to participate in this study during their classes. The native-English participants at MSU were provided a consent form for soliciting their participation which was a part of the MSU Institutional Review Board (IRB) requirements. The consent form described the purpose of this study, its importance, and the procedures involved. The benefits and risks were also explained (see Appendix C for details). From several calculus classes, 132 English speakers and 126 Korean speakers were recruited to take the survey on the basis of instructors’ agreement to data collection in their classroom and students’ willingness to participate. The volunteers were informed that they might be selected for the further paired interviews after completing the questionnaire. Of those volunteers in each university, twenty students were selected for paired interviews based on their responses to the questionnaire. The following procedures were used in selecting interview participants. First, I looked at whether the participants had studied mathematics before in any language other than their native language; any participant who had done so was not considered as a possible interviewee. Second, different kinds of students were selected in terms of their responses to the questionnaire based on their previous curricular experience with infinity and limit. The selection of those students in terms of their curricular experience improved the validity of the data for the proposed study (Patton, 2002), because the selection of students from various levels can be more representative of the population. To examine students’ intended curricular experience with infinity and limit, the textbooks students used in high school were analyzed. Table 3.3 summarizes percentages 35 of the English-speaking participants’ and Korean-speaking participants’ written responses to the question about high school textbooks. Table 3.3 Percentages of students’ responses to the question about high school textbooks 1.:sz K-participants K-interviewees “35:ka E-participants E-interviewees K1 9 (7.1%) 2 (10.0%) USl l (0.8%) 0 (0.0%) K2 12 (9.5%) 2 (10.0%) U82 1 (0.8%) 0 (0.0%) K3 10 (7.9%) 2 (10.0%) US3 0 (0.0%) 0 (0.0%) K4 1 (0.8%) 0 (0.0%) U84 14 (10.6%) 4 (20.0%) K5 9 (7.1%) 2 (10.0%) USS 20 (15.2%) 4 (20.0%) K6 26 (20.6%) 4 (20.0%) U86 4 (3.0%) 2 (10.0%) K7 13 (10.3%) 2 (10.0%) US7 24 (18.2%) 4 (20.0%) Mixed 31 (24.6%) 6 (30.0%) Mixed 7 (5.3%) 0 (0.0%) Others 9 (7.1%) 0 (0.0%) Others 53 (40.2%) 6 (30.0%) No remnse 6 (4.8%) 0 (0.0%) No response 8 (6.1%) 0 (0.0% Total 126 (100%) 20 (100%) I32 (100%) 20 Q00%L In order to ensure that the selected interviewees were representative of each population in terms of curricular experience, I selected the number of interviewees within each category on the basis of the ratio of the number of students in each category to the total number of students. For instance, because the ratio in the K6 category is 21% (the number of students (n = 26) / the total number of the Korean students), four interviewees were selected within the K6 category among the total of twenty selected interviewees. After deciding the number of interviewees within each category based on their curricular experience, a random selection procedure was used to choose interviewees within the category. For instance, in the US7 category, 4 students were randomly selected out of the total of 24 students. If a student declined to participate in paired interview, another random selection was conducted with all of the students in each category, excluding the student who declined to participate in the interview. The following paragraph describes the interview method for this study. The method of interviewing pairs of students, who solved problems together with minimal participation of the interviewer, was used because this type of interview may further 36 reveal mechanisms of student thinking (especially in terms of routines in the first research question) rather than interviewing a single student by a researcher. That is, student thinking processes were monitored through paired problem solving. A pair of students was able to watch each other’s errors, probe the other student’s understanding, and help each other to reach a deeper level of comprehension. To ensure the occurrence of the listed three advantages of the paired problem solving, I helped pairs of students to continuously verbalize their thoughts aloud and express the major steps they used to solve each mathematical problem on the questionnaire. I also assisted each pair of students to clarify his or her thoughts for details whenever the listener was not sure of how the problem solver was thinking (Whimbey and Lochhead, 1984). The following possible prompts were used: “Can you explain how to come to your answer step by step?”, “What do you mean by the word you just used?”, and “Can you explain more about what you just said?” This was a way to monitor student thinking and reduce interviewer’s effects and biases on students’ responses. The interviews, which were conducted in the participants’ first language, took as much time as the participants needed to respond to the problems in the discourse questionnaire. For pairs of students to concentrate on a given problem, one small card listing each term or each problem was prepared and shown to interviewees during the interviews. For instance, the problems in the first category were given to interviewees on a card with only one word written on it, such as infinity and limit. The interviews took place in a university office, or another convenient location. All interviews were audio- taped, video-taped, and transcribed in their entirety for further analysis. As compensation, each interviewee received 25 dollars. The Korean-English bilinguals (three mathematics 37 educators and one linguist who helped the Korean translations of the survey questionnaire into English) assisted in transcribing the Korean interviews into English. Analysis Analysis of Former Education To analyze and categorize students’ written responses to the questions regarding former education in the background questionnaire, the columns of course and content were used to search for variations in different levels of previous education. For instance, the following categories were used for responses to the questions about limit (see Table 3.4). Compared to those university students who did not learn about the concept of limit in their secondary education, university students who learned about limits when taking Pro-calculus or Calculus in high school may respond differently to the notion of limit because of their different degrees of exposure to limit. Similarly, the content column was used to select different levels of students in terms of different experiences and degrees of difficulties with the concept of limit. Table 3.4 The course and content categories for limit Course Content Algebra Limits to infinity Geometry The 8-8 (epsilon-delta) definition of limit Advanced Algebra Limit of a sequence or series Pre-calculus Limit of a function numerically Calculus Limit of a function geometrically L Limit and the definition of continuity Limit and the definition of the derivative Analysis of Intended Curricula Intended curriculum in this study means planned learning experiences in terms of Standards or frameworks at the national or state level, as well as instructional guides and 38 textbooks. Thus, instructional materials and policy documents were used for intended curricular emphases. As noted, information about instructional materials was collected on the basis of students’ written responses to the questions regarding the textbooks that they used. However, due to the complexity of curricular experience, interviewees were selected as representative of each population in terms of their curricular experience rather than analysis of their textbooks. Discourse Analysis The transcribed data from paired interviews were used as a primary source to analyze students’ non-mathematical and mathematical discourses. Through paired problem solving, students’ non-mathematical and mathematical discourses on infinity and limit were recorded, transcribed and coded according to the four features of discourse. Then, interview data were analyzed in order to identify and describe those four features. Because of the nature of the questions asked, only a subset of the four features was depicted in each category. At the next stage, the analysis of the data was guided by the three research questions of this study. In each of the four features, the representative analysis samples were elicited from the pilot study (see Appendix B for details). Based on the four features, I deduced hypotheses to relate characteristics in mathematical discourse to those in non- mathematical discourse and curricular experience. Finally, I examined similarities and differences of these hypothesized relationships between native-English and native- Korean speakers. To decide what to include and focus on from the entirety of the conversations, my analytic decisions were based on representatives of general themes through the interview rather than on outliers. Repeated parts were also dropped. 39 Therefore, only a sample of representative utterances was presented in the results. The theoretical components (the four distinctive features of colloquial and mathematical discourses) which each item assesses are summarized in Table 3.5. Table 3.5 Theoretical components assessed by each item Theoretical components category Word use Visual mediators Routines Egg: 1 «l 4 ll w/ «I w/ Ill ‘l \l J IV «I J V J ~/ «I VI \/ w/ VII 4 w/ VIII «I ~/ 40 CHAPTER IV ANALYSIS AND FINDINGS This chapter is divided into two main sections. The first section describes the overall characteristics of the survey participants’ backgrounds relative to mathematical learning, using descriptive and inferential statistical results of all the participants’ responses to the survey questionnaire. The second section provides a characterization of the participants’ colloquial and mathematical discourses, drawing on analyses of all the participants’ written responses to the survey, as well as analyses of the interview data of twenty representatives in pairs within each linguistically distinct group. The analyses in the second section are organized to identify the primary features of the participants’ colloquial and mathematical discourses on infinity and limit. Background Datgpbout the Students and their Past and Present Mathematical Learning In this section, I will discuss students’ past and present mathematical learning, and will present an analysis of the 126 Korean and 132 English speaking students’ written responses to the background questions in the survey. For the second research question, this analysis of the background data will generate differences between the Korean and English speaking groups in their former mathematics education and curricular experiences with infinity and limit. To investigate whether or not there is a statistically significant background difference between the two groups on categorical variables, Pearson’s chi-square statistics (with alpha set at .01) in Statistical Package for the Social Sciences 16.0 for Windows (SPSS Inc., 2007) were used because most of the items on the background questions measure categorical variables. One of the important assumptions of chi-square is that the minimum expected cell frequency should be 5 or greater (Pallant, 41 2005). If the minimum expected count violated this assumption, two or three categories were collapsed into one category to use chi-square analysis. For background items measuring a continuous variable, an independent samples t test was conducted to compare the mean score for the two groups. Chi-square analysis compares the proportions of the two groups rather than their means as in the case of the t test. The background survey consists of 21 questions. Most of the questions were either adapted or borrowed from the student questionnaire of the Third International Mathematics and Science Study (TIMSS, 2003). These 21 questions are aimed at investigating demographic information about the participants, their attitudes toward mathematics learning, and characteristics of their formal education related to infinity and limit. This questionnaire provides not only the information about students’ background, but also their past and present mathematics learning about infinity and limit. Students’ Background Personal background Table 4.1 presents a summary of the demographic characteristics of the Korean and English speaking participants (K-participants and E-participants) in the survey study. In total, the 126 Korean and 132 English speaking university students participated in this study from three and six classrooms respectively. The 126 Korean speakers (K-speakers) consisted of 31 (24.6%) females and 95 (75.4%) males. Of the 132 English speakers (E- speakers), 37 (28.0%) students were female and 95 (72.0%) were male. The grade levels of the K-speakers were as follows: 123 (97.6%) freshmen, 1 (0.8%) sophomore, and 2 (l .6%) juniors. The E-speakers were composed of 109 (82.6%) freshmen, 15 (11.4%) sophomores, 6 (4.5%) juniors, and 2 (1.5%) seniors. 42 One hundred percent of the K-participants said that they spoke Korean as their native language. The majority (84. l %) of the E-participants stated that they had English as their native language and 15.9% (n=21) participants, including five Koreans, reported “other” as their native language. The majority (83.3%) of the K-speakers responded that they were studying calculus in English due to the use of the English calculus textbook in their classroom. However, the language of instruction in class was not English, but Korean. The majority (86.4%) of the E-speakers replied that they had not been exposed to other languages in learning mathematics. Both their instruction and their textbook was in English. Table 4.1 Demographic characteristics of the survey participants K-speakers E-speakers (n = 126) (n = 132) 0. Gender Male 31 (24.6%) 37 (28.0%) Female 95 (75.4%) 95 (72.0%L 1. Year Freshman 123 (97.6%) 109 (82.6%) Sophomore l (0.8%) 15 (11.4%) Junior 2 (1.6%) 6 (4.5%) Senior 0 (0.0%) 2 (1.5%) 2. Native Language Korean 126 (100.0%) 5 (3.8%) English 0 (0.0%) III (84.1%) Other 0 (0.0%) 16 (12.1%) 3. How often do you speak Always 120 (95.2%) l 14 (86.4%) your native language at Almost always 4 (3.2%) 16 (12.1%) home? Sometimes 2 (1.6%) l (0.8%) Never 0 (0.0%) 0 (0.0%) No response 0 (0.0%) l (0.8%) 4. About how many books 0-10 books 7 (5.6%) 4 (3.0%) are there in your home? 1 l-25 books 13 (10.3%) 10 (7.6%) (Do not count magazines, 26-100 books 33 (26.2%) 39 (29.5%) newspapers, or your 101-200 books 28 (22.2%) 33 (25.0%) school books) More than 200 books 45 (35.7%) 46 (34.8%) On the question regarding how often the participants speak their native language at home, 95.2% of the Korean speaking group (K-group) and 86.4% of the English speaking group (E-group) answered “always.” With respect to the question on the number of books which the participants estimate having at home, this survey indicated 43 that there was no significant difference between two linguistically different groups in terms of the chi-square statistic (x2 = 1.99, p > .01). Mathematics background To investigate and categorize variations in different levels of former education, students’ written responses to the background questions regarding textbooks used and courses taken in high school were analyzed. Table 4.2 Summary of textbooks used in higr school Korean K-speakers U.S. E-speakers Textbooks (n = 126) Textbooks Q1 = 132) K 1 9 (7.1%) US l l (0.8%) K 2 12 (9.5%) US 2 l (0.8%) K 3 10 (7.9%) US 3 0 (0.0%) K 4 1 (0.8%) US 4 14 (10.6%) K 5 9 (7.1%) US 5 20 (15.2%) K 6 26 (20.6%) US 6 4 (3 .0%) K 7 13 (10.3%) US 7 24 (18.2%) Mixed 31 (24.6%) Mixed 7 (5.3%) Others 9 (7.1%) Others 53 (40.2%) No response 6 (4.8%) No response 8 (6.1%) Table 4.2 indicates that about 90% of the K-speakers said that they studied from one or more of the seven representative textbook examples in the survey, whereas only 53.7% of the E-speakers answered that they used one of the seven examples in high school (see Appendix C for the examples). Of the K-speakers, 24.6 % reported that they used multiple textbooks in the examples rather than one textbook series, and 5.3 % of the E- speakers reported the same thing. Table 4.3 Summary of course series taken in high school Korean courses Iii-15:63:? U.S. courses E (Zing?) Math Application 4 (3 .2%) Pre-Algebra 13 (9.9%) Mathematics 10 l 10 (87.3%) Algebra or Algebra 1 62 (47.0%) Mathematics 1 115 (91.3%) Geometry 83 (62.9%) Mathematics 11 114 (90.5%) Advanced Algebra/Algebra 2 91 (68.9%) Calculus 112 (88.9%) Pre-Calculus/Calculus 114 (86.4%) Others 0 (0.0%) Others 4 (3.0%) No response 10 (7.9%) No response 29 (22.0%L 44 Table 4.3 demonstrates that about 90% of the K-speakers who responded to the question about courses taken in high school said that they took courses consistently in the series from Mathematics 10 to Calculus. In contrast, only 47.0%, 62.9%, and 68.9% of the E-speakers reported that they took Algebra 1, Geometry, and Algebra 2 respectively, in high school. Another question was asked in order to inquire about the most advanced mathematics course that students took in high school. Of the K-speakers, 90.5 % answered that they did not take any course other than calculus. However, 88.9% of the K- speakers reported that they took calculus in high school as part of a course series taken in high school. Comparatively, 86.4% of the E-speakers claimed that they took either Calculus or Pro-Calculus in high school as the most advanced mathematics course taken in high school. Experience with infinity and limit To examine the participants’ experience with the mathematical words infinity and limit, they were asked to recall the first mathematics course in which they heard the terms. Table 4.4 shows a summary of frequencies and percentages of the participants’ responses to the question about their experiences with the words infinity and limit. Seventy seven percent of the K-speakers responded that they remembered the first mathematics course in which they heard the word infinity, compared to about 50 % of the E‘Speakers. Of the K-speakers, 88.9 % reported that they recalled the first use of the word limit in a mathematics course, whereas 84.1 % of the E-speakers said that they remembered hearing the word in a mathematics class. Chi-square analysis of this distribution indicated that the K-speakers were significantly more likely to report 45 4) can!) 15mm. ”3' all.» J ' I oo’ .r-l c remembering the first mathematics course in which they heard infinity (x2 = 19.15, p < .001), but there was no significant difference between the K-group and E-group in remembering the first use of limit in their mathematics course (x2 = 1.27, p > .01). Table 4.4 Summary of the participants’ recollection of experiences with iryinity and limit K-speakers E-speakers (n = 126) (n = 132) 6. Can you remember the first math course in Yes 97 (77.0%) 67 (50.8%) which you heard the word (mathematical) infinity? No 29 (23.0%) 65 (49.2%) 7. If yes, specify in which grade(s) and in which 2 0 (0.0%) 1 (0.8%) course/class you heard the word (mathematical) 4 4 (3.2%) 2 (1.5%) infinity. 5 2 (1.6%) 3 (2.3%) 6 5 (4.0%) 3 (2.3%) 7 16 (12.7%) 9 (6.8%) 8 18 (14.3%) 8 (6.1%) 9 7 (5.6%) 7 (5.3%) 10 17 (13.5%) 13 (9.8%) 11 26 (20.6%) 13 (9.8%) 12 0 (0.0%) 7 (5.3%) 14 0 (0.0%) l (0.8%) No response 31 (24.6%) 65 (49.2%) 8. Can you remember the first math course in Yes 1 12 (88.9%) 111 (84.1%) which you heard the word (mathematical) limit? No 14 (11.1%) 21 (15.9%L 9. If yes, specify in which grade(s) and in which 6 0 (0.0%) l (0.8%) course/class you heard the word (mathematical) 8 0 (0.0%) 2 (1.5%) limit. 9 6 (4.8%) 6 (4.5%) 10 29 (23.0%) l6(12.1%) ll 77 (61.1%) 42 (31.8%) 12 0 (0.0%) 33 (25.0%) 13 0 (0.0%) 10 (7.6%) 14 0 (0.0%) l (0.8%) No response 14 (11.1%) 21 (15.9%) On the question regarding the grades in which they heard the words infinity and limit, Overall response rates are the same as the percentage of the participants who answered “y 68” for the previous question. For instance, about 75% of the K-speakers and 50% of the E-speakers did specify grades in which they recalled having first heard the word infinity. Among the students who specified a grade, the range of grades was from 4th to I l th grade in the K-speakers’ responses. The range of grades of the E-speakers’ responses was more varied, from 2nd to 14th grade. This survey result also indicated that the maj ority (84.1%) of the E-speakers’ responses had a variety of grades relative to first 46 hearing the word limit, ranged from 6th to 14’h grade as compared to the majority (88.9%) of the K-speakers who said that they first heard the word limit between 9’“ and 11’” grade. Table 4.5 Grades in which students recalled first hearing the words infinity and limit Word K-speakers (n=l26) E-speakers (n=l32) M (SD) M (SD) df t-score Infinity 8.75 (1.99) 9.01 (2.37) 160 - .78 Limit 10.63 (0.59) 11.15 (1.22) 158.09 - 4.06‘ The grade items were analyzed using attest because grade is a continuous outcome variable. In the case of the question about the participants’ recollection of the grade in which they were first introduced to the word infinity, equal variance was assumed because the significant value of Levene’s test for equality of variances was larger than 0.05. The t test [t (160) = -.78, p > .01] confirmed no significant difference between the K-group and E-group in the range of grades in which they first heard infinity. In the case of the same question about the word limit, equal variance is not assumed because the result of Levene’s test was significant. Interestingly, the t test result [t (158.09) = -4.06, p < .01] revealed that the mean of the E-speakers’ responses to grade was significantly higher than that of the K-speakers, as shown in Table 4.5. In order to indentify the topics related to the words infinity and limit which students studied in high school, seven concept categories within each term were considered. Tables 4.6 and 4.7 show percentages of students reporting that they had studied particular topics related to infinity and limit in high school as well as the results of chi-square comparing the percentages of each concept category in the two groups. Pearson’s chi- square statistics were employed to compare the percentages of the K-group and the E- group in each concept category. 47 Table 4.6 Percentages of students reporting having studied specific topics related to infinity in highschool and the results of chi-square 13. Please check the box(es) to topic K-speakers E-speakers Chi-square Wthh you have studied. (n =126) (n = 132) Value Significance Level a Infinite processes 42.9% 47.0% 3.69 .06 b. Infinite decimal fractions 84.9% 45.5% 34.95 .000" c. Infinite sequence or series 91.3% 61.4% 23.94 .000* d The sum of infinite geometric series 75.4% 50.8% 8.48 .004“ e. Comparison of infinite sets 46.8% 32.6% 2.00 .16 f Countable and uncountable sets 69.8% 18.9% 58.51 .000" g. Infinitely small or infinitesimal 46.0% 36.4% .33 .57 Note. "‘ The percentage difference is significant at the 0.01 level. In the case of infinity, the chi-square analysis confirmed a significant difference between the K-group and E-group in categories b, c, d, and f. The results revealed that the percentage of K-speakers who reported having learned each of the four concepts was significantly different from the percentage of E-speakers who reported having learned the same concept. Table 4.7 Percentages of students reporting having studied specific topics related to limit in high school and the results of chi-square 14. Please check the box(es) to topic which K-speakers E-speakers Chi-square You have Smdled- (n = 126) (n =l32) Value Sig. 0. Limits to infinity 86.5% 77.3% 5.21 .022 b. The 3-8 definition of limit 14.3% 31.8% 1 1.22 .001 " 0. Limit of a sequence or series 88.1% 53.0% 44.23 .000“ (1 Limit of a function numerically 61.1% 65.9% .66 .42 e. Limit of a function geometrically 60.3% 52.3% 1.90 .17 f Limit and the definition of continuity 92.9% 65.2% 38.00 .000" 81.0% 65.2% 9.86 .002“ g. Limit and the definition of the derivative Note. Sig; = significance level. "‘ The percentage difference is significant at the 0.01 level. In the case of limit, the differences in categories b, c, f, and g were large enough to be statistically significant. It is notable that the percentage (31 .8%) of the E-speakers who reported having studied the 3-5 definition of limit in high school was significantly higher than that (14.3%) of the K-speakers, whereas the percentages of the E-speakers who stated that they learned the other topics were less than those of the K-speakers at statistically significant levels. 48 ll'" '93. r [A r‘/ u ’; fir»- ..f‘ Summary In summary, most E-speakers and K-speakers in the survey were freshmen and the ratio of males to females was similar between the E—group and K-group. The majority of the E-speakers said that they were exposed only to English in learning mathematics, and the majority of the K—speakers answered that they studied mathematics in Korean with the use of an English textbook (Thomas, 2005) in their calculus classrooms. However, in most cases the K-speakers were exposed to the English textbook only recently. This English textbook was used at the university, whereas high schools in Korea use Korean mathematics textbooks. The E-speakers reported that they used a variety of textbooks in high school other than the representative examples in the survey, whereas the majority of the K-speakers said that they studied from the seven textbook examples. E-speakers also claimed that they took courses less consistently in the course sequences than the K-speakers. It is noteworthy that even though the majority of the E-speakers and K-speakers reported taking either Pre-calculus or Calculus in high school, K-speakers indicate that the calculus course is required, whereas E-speakers imply that US. pre-calculus or calculus is optional. Note that the non-response rate of the E—speakers is more than double that of the K-speakers on the item about course series taken in high school. This is probably not only because some of the E-speakers took different course sequences from the Algebra 1 — Geometry - Algebra 2 sequence, perhaps through the use of integrated curricula, but also because they studied from textbooks other than the survey examples. As for experience with infinity and limit, it seems to be easier for students to remember when they first heard the word limit in a mathematics course than to remember 49 when they first heard the word infinity. More K-speakers responded that they remembered the first mathematics course experience about infinity compared to E- speakers. However, there was no significant difference between the two groups in the range of grades in which they first heard infinity. In the case of limit, there was no significant difference between the two groups in remembering the first mathematics course experience about limit. However, the E-speakers varied significantly in their responses to the question regarding the grade in which they heard the word limit. As for the topics related to the words infinity and limit which students studied in high school, K- speakers reported that they had studied most of the seven categories related to the words infinity and limit at higher rates than the E-speakers. This is probably because the K- speakers had studied more topics related to infinity and limit in their high school curricula. Students’ Current Mathematics Learning Description of the calculus classes in the U.S. and Korea The calculus courses in the U.S. institution which is the site of this study are 3-credit classes taught by faculty and post-doctoral instructors. The U.S. class meets on Monday, Wednesday, and Friday for 50 minutes, and has a class size that is usually under 35 students. Chapters 2 through 5 of Thomas’ calculus book (Thomas, 2005) are covered during the semester. The U.S. calculus course is planned so that students take four one- hour tests and a two-hour final examination. Each test covers approximately one chapter in Thomas’ calculus book. The final exam is a comprehensive examination which covers all the content from chapters 2 through 5. A lab course is designed for the U.S. calculus course. This lab course as a 2-credit class is offered on a voluntary basis for students who want extra work and more credits. This lab class meets Monday, Wednesday, and Friday 50 and students are required to attend class. In the lab class, students complete worksheets and solve problems to review the content of the calculus course. In the fall of 2007, about 5 % (30 out of 983 students) of the total number of students in the calculus course took the lab course. The calculus class in Korea University is a 4-credit class taught by faculty and post- doctoral instructors. The Korean class meets on either Monday and Wednesday or Tuesday and Thursday for one hour and fifteen minutes. The size of each class is generally under 60 students. Chapters 1 through 12 of Thomas’ calculus book (Thomas, 2005) are covered during the semester. Some sections of the textbook are not covered during the course, In the calculus class, students are required to take two two-hour tests and a two-hour final examination. Each test covers about four chapters in Thomas’ calculus book. However, the final is not a comprehensive examination and covers the content learned afier the second test. Part of the class also includes a 50- to 80-minute drill period every week. During the period, students solve problems in the calculus textbook. Student ’s self-report on their learning of mathematics As context for interpreting the particular findings of this research relative to E- speakers’ and K-speakers’ understanding of infinity and limit, data were gathered to determine the speakers’ perception of the calculus instructional setting. In order to understand how students perceive their learning of mathematics in the classroom, each classroom environment item was rated with the four categories of frequency in mathematics lessons (‘Never,’ ‘Some lessons,’ ‘About half the lessons,’ and ‘Every or almost every lesson’). Table 4.8 shows percentages of the participants’ responses to the 51 questions about their classroom environments and the chi-square results of the comparison of the E-speakers’ and K-speakers’ responses about the mathematics lesson items. The lowest expected frequency in any cell should be 5 (about four percent) or more to use chi-square statistics. If the expected frequency was less than 5, a method of collapsing two or three categories into one category was used. For the classroom environment questions with the minimum expected counts less than 5 (e.g., 17-a, 17-b, and 17-f), for instance, the ‘Never’ category and the ‘Some lessons’ category were combined together into one category and the ‘Almost every lesson’ category and the ‘About half lessons’ category were collapsed into another category. Table 4.8 Percentages of students’ responses to the classroom environment items and the chi-scmare results 17. How often do you do these things Almost About Some No Chi-square in your mathematics lessons‘7 every halfthe lessons Never response - ' lesson lessons df Value 518- 17-21. We work together in small K 3.9 6.4 20.6 68.3 0.8 1 2 32 l 3 groups. B 2.3 3.0 25.8 68.9 0.0 ' ' 17-b. We relate what we K 2.4 7.1 45.2 45.2 0.0 1 12 91 learning in math to daily lives. E 4.6 5.3 33.3 56.1 0.8 ' ' . K 2.4 12.7 50.0 34.1 0.8 ,, I7-c. We explain our answers. E 33.3 25.0 29.5 12.1 0.0 3 59.52 .000 l7-d. We decide on our own K 8.7 34.9 45.2 9.5 1.6 3 25 84 000,, procedures for solving problems E 9.9 16.7 39.4 33.3 0.8 ' ' . K 15.9 27.8 38.9 16.7 0.8 ,, 17-e. We revuew our homework E 19.7 14.4 26.5 39.4 0.0 3 20.85 .000 17-f. We listen to the teacher’s a K 70.6 19.0 7.9 1.6 0.8 1 2 52 1 l lecture-style presentation E 90.2 5.3 2.3 213 0.0 ° ' I7-g. We work problems on our K 18.3 37.3 38.1 5.6 0.8 , own. E 38.6 18.2 21.2 22.0 0.0 3 36'59 '000 I7-h. We use calculators K 0'8 1'6 27.8 69'0 0'8 3 19.40 .000" E 9.9 9.1 18.2 62.9 0.0 Note. K = K-speakers; E = E-speakers; Sig. = significance level. *The distribution differences are significant (p S .01). There were statistically significant differences between the E-group and K-group in items 17-c, 17-d, 17-e, 17-g, and 17-h. In classrooms, the K-speakers said that they had more opportunities to use their own procedures for solving complex problems and spent more class time to review their homework, as shown in items 17-d and 17-e respectively. 52 In contrast, items 17-c, 17-g, and 17-h show that the E-speakers reported that they had more opportunities to explain their answers, work on problems on their own, and use calculators in their classrooms. Note also that there were no significant differences in E- speakers’ and K-speakers’ reports about use of small group work in the calculus classroom (neither group reports this occurring very much); that both groups report few opportunities to relate calculus to their daily lives, and that both groups report a similar prevalence of lecture-based instruction. Table 4.9 Percentage distributions of extra lessons and homework and the chi-square results , . . K-speakers E-speakers Chi-square Ques’w“ categmes (n = 126) (n = 132) df Value Sig. 19. During this school Every or almost every day 0.8 2.3 year, how often have you Once or twice a week 1.6 10.6 had extra lessons or Sometimes 0.0 24.2 I 10.05 .002“ tutoring in math that is not Never or almost never 97.6 62.1 part of your regular class? No response 0.0 0.8 Every day 1.6 60.6 20. How often does your 3 or 4 times a week 0.0 27.3 . . 1 or 2 times a week 97.6 6.1 instructor give you 1 195.59 .000“ homework in math? Less than once a week 0.8 0.8 Never 0.0 4.6 No response 0.0 0.8 Fewer than 15 minutes 2.4 18.9 21. When your instructor 15-30 minutes 2.4 13.6 gives you math homework, 31-60 minutes 25.4 34.1 4 47 78 000,, about how many minutes 61-90 minutes 37.4 14.4 ' ' are you usually given? More than 90 minutes 32.5 16.7 No response 0.0 2.3 Note. Sig. = significance level. *The distribution differences are significant (p S .01). Questions on extra lessons in mathematics that were not a part of regular class and mathematics homework were also asked. Table 4.9 shows the percentage distributions of extra lessons and homework in mathematics and the chi-square results of the comparison 0f the E-speakers’ and K-speakers’ responses about the extra lessons and mathematics homework items. Because the expected frequency is less than 5 in the question on extra lessOns in mathematics, the first two categories (‘Every or almost every day’ and ‘Once or tvVice a week’) were combined together into one category and the other two categories 53 (‘Sometimes’ and ‘Never or almost never’) were collapsed into another category to use chi-square statistics. In the next question on frequency of mathematics homework, because the minimum expected count was .98, a method of collapsing categories was to combine the first two categories (‘Every day’ and ‘3 or 4 times a week’) into one category and the other three categories (‘1 or 2 times a week,’ ‘Less than once a week,’ and ‘Never’) into another category. Finally, in the question on length of mathematics homework, no collapsing method was considered because the minimum expected count is bigger than 10. There was a statistically significant association between the E-speakers and extra lessons. In other words, the E-speakers reported that they had more extra lessons or tutoring than the K-speakers (x2 = 10.05, p < .01). Seventeen of 132 E-speakers had extra lessons at least once a week, compared with three of 126 K-speakers. The results of the chi-square analysis revealed that there were statistically significant differences between the K-group and E-group for frequency and length of mathematics homework. The statistically significant difference (x2 = 195.59, p < .001) was observed in frequency of mathematics homework. The statistical result shows that the E-speakers were assigned more homework than the K-speakers. Chi-square analysis of this distribution indicated a significant difference (12 = 47.78, p < .001). The K-speakers were significantly more likely to report spending time doing mathematics homework than the E-speakers. Out-of-school activities Nine items were asked to explore possible differences between the two linguistically distinct groups in the ways that out-of-school time was spent on a typical school day. Table 4.10 displays a summary of percentages of students’ responses to the questions 54 regarding activities before or after school and the results of chi-square to the extent of time spent out-of-school activities. Table 4.10 Percentages of students’ responses to the out-of-school activity items and the chi-square results 18. On a normal school day, how No Less 1-2 More No Chi-square much time do you spend before/after time than 1 hours than 2 res ns e d V 1 8' school doing each of these things? hour hours p0 f a ue 1g. 18-a. I watch television and K 30.2 43.7 17.5 8.7 0.0 ,, videos E 10.6 37.1 31.8 20.5 0.0 3 24'28 '000 K 36.5 32.5 19.8 10.3 0.8 l8-b. I play computer games E 54.5 2 5. 8 9.9 9.1 0. 8 3 10.08 .02 18-c. 1 play or talk with K 1.6 31.0 38.1 27.8 1.6 ,, friends E 0.0 12.1 39.4 48.5 0.0 1 162° °°°° . K 44.4 44.4 6.4 1.6 3 .2 ,, 18-d. 1d0jobs at home E 27.3 52.3 14.4 6.1 0.0 1 7.66 .006 . . K 73.8 2.4 11.1 12.7 0.0 18-e.Iworkatapa1djob E 64.4 4.6 6.1 25.0 0.0 1 1.70 .19 K 32.5 48.4 15.1 3.2 0.8 , ’8": I play 31”“ E 22.7 29.5 31.8 15.9 0.0 3 26'6’ '000 18-g. 1 read a book for K 37.3 48.4 10.3 3.2 0.8 1 1 0] 32 enjoyment E 42.4 39.4 15.2 3.0 0.0 ' ' . K 0.8 20.6 47.6 30.2 0.8 18-h. I use the mtemet E 0.0 1 3. 6 3 8. 6 47.7 0.0 l 2.82 .09 . K 3.9 22.2 46.8 27.0 0.0 ,, 18-1. 1 do homework E 0.0 10.6 43.9 45.5 0.0 l 10.51 .001 Note. K = K—speakers; E = E-speakers; Sig. = significance level. *The distribution differences are significant (p S .01). Each item on activities before or after school was encoded on the basis of the following four categories (‘No time,’ ‘Less than 1 hour,’ ‘ 1-2 hours,’ and ‘More than 2 hours’). Because the minimum expected frequencies of items 18-c, 18-d, l8-e, 18—g, 18-h, and 18-i were less than 5 (about four percent), the first two categories (‘No time’ and ‘Less than 1 hour’) and the other two categories (‘ 1-2 hours’ and ‘More than 2 hours’) were collapsed into one and another categories respectively to use chi-square. The chi- square results indicate that the E—speakers answered that they used more time than the K- speakers on accomplishing most activities. In order to investigate the extent of time spent out-of-school activities on average, each item on activities before or after school was encoded based on the following scores 55 (0 = ‘no time,’ 1 = ‘less than 1 hour,’ 2 = ‘1-2 hours,’ and 3 = ‘more than 2 hours’). The mean (M) and the standard deviation (SD) results for each item were summarized in Table 4.11. Table 4.11 Mean (M) and SD results to the extent of time spent out-of-school Item K I:Ipeakgrls) Elsipeakesrls) 18-a. I watch television and videos. 1.05 0.91 1.62 0.93 18-b. I play computer games. 1.03 1.00 0.73 0.97 18-c. I play or talk with friends. 1.90 0.84 2.36 0.69 18-d. I do jobs at home. 0.62 0.68 0.99 0.82 18-e. I work at a paid job. 0.63 1.1 l 0.92 1.31 18-f. I play sports. 0.88 0.78 1.41 1.01 18-g. I read a book for enjoyment. 0.79 0.76 0.79 0.81 18-h. I use the intemet. 2.06 0.76 2.34 0.71 18-i. I do homework. 1.97 0.81 2.35 0.67 The descriptive statistic of item 18-i, for instance, shows that the E-group had a mean score of 2.35 with a SD of .67 in time spent on doing homework on a usual school day, which indicates that the E—speakers reported spending about one hour and 20 minutes on average doing homework on a typical school day. In contrast, the K-group had a mean score of 1.97 with a SD of .81, which reveals that the K-speakers spent about an hour on average. Students ’ way of life The results about students’ engagement in mathematics outside of the course (e.g., extra lessons, homework, etc.) reported in Table 4.9 raised additional questions about whether there were indeed differences in what was happening outside of class with students in these courses, and what the nature of those differences might be. In order to gain additional insights about how students were studying mathematics, all English speaking and Korean speaking interviewees (E-interviewees and K-interviewees) were asked about the length of time they were spending studying and their study methods, to 56 plT‘n e" ‘Al‘al oln - hi‘uha ‘JJ has provide descriptions of their typical weekday in their typical week via email. In the emails, the following two questions were asked: 1) Could you please describe how many hours and in what kinds of format (e. g., group study, tutoring, study alone) you studied calculus in a typical week last semester? 2) Could you please describe your typical weekday? Your weekends? And your holidays? Table 4.12 Summary of students’ descriptions of how to study calculus Students Students’ descriptions of how to study calculus I mainly reviewed contents at night on Monday and Wednesday when I had class. If there was a test coming up, 1 studied at night on Monday, Tuesday, and Friday. I studied by looking at the textbook and solving examples. ..I studied alone for about 2 hours at night on Monday and Wednesday. Because 2 o'clock on Saturday would be the examination time, I studied alone from about 5 pm when class was over to 12 o'clock and Friday night and Saturday morning. . .I followed my class schedule during the week. K-speakers In class, I roughly wrote the professor’s notes from the blackboard in my workbook ...And then I reviewed contents that were covered in class by transcribing them from the workbook into my notebook after class was over. ..So I worked in this way. I studied contents in the textbook alone and solved problems related to them. I solved homework problems first alone, and then gathered with fi'iends later and compared answers. If there were problems which I did not solve alone, I solved them with the help of friends. ..I tried to be faithful to my school life during the week. (In the given time table, she wrote “reviewing notebook” on Tuesday and Thursday and “group study” on Friday) 1 often make the unwise choice of waiting until the night before a test or quiz to start studying for it. . .The only way I can learn is if I sit down in a quiet place and read the text book while doing example problems, or having a tutor sit down next to me and personally explain the material...l have good intentions to study, but I usually end up wasting a lot of time sitting around talking to my friends. (In the given time table, he wrote “alone” several times on Mondgy thrmgh Sunday) On weekdays, I go to class and do whatever homework is due the following day around 9 or 10 at night. On weekends, I finish all the homework I possibly can for the upcoming week, and any reading that I missed over the preceding week. (In the given time table, she wrote “1 (hour)” on Monday, Wednesday, and Friday and “alone or Math Learning Center for 4 (hours)” on Sunday) E-speakers My typical weekday involves going to my classes and then relaxing for a little while once I get home. I usually do homework before and after dinner... My weekends involve studying and spending time with fi'iends. (In the given time table, she wrote “study alone” several times on Monday through Sunday and “study alone or Math Learning Center for “a half hour” on Thursday) (In the given time table, he just wrote “do problems out of the book” and “2 (hours)” on Tuesdayand Thursday and “1 (hour)” on Sunday) Four E-interviewees and two K-interviewees responded to those questions in March and April 2008 (see Appendix D for their entire responses; notice that K-interviewees were interviewed in May 2007, compared to E-interviewees in September and October 2007 due to different systems of academic year). Table 4.12 is a summary of the 57 students’ descriptions of how they studied calculus. The students’ responses provide a more refined view on how the two groups of students are studying. Two K-interviewees reported that they had everything systematically planned including study methods, periods of rest and they spent time exactly according to that plan. In contrast, the four E- interviewees appeared to have planned less and admitted to not being able to follow it too tightly even if they had a plan. These responses, although from a very small sample of students, could suggest that the K-speakers are more serious about their studying, more carefully organized, and devote more thought and more time to it than the E-speakers. For the K-speakers interviewed here, studying is more central in their lives, compared to the E-speakers. Summary Students in this study reported that they listened to teachers’ lecture-style presentation in both U.S. and Korean classrooms for more than half of the lessons. In classrooms, the K-speakers replied that they used their own procedures more flexibly for problem solving. However, the E-speakers responded that they had more opportunities to explain their answers and use calculators. According to student responses, K-speakers may be spending more class time reviewing their homework than the E-speakers, probably because of the 50- to 80-minute drill period every week. The E-speakers reported that they spent more time on homework at home on a normal school day than the K-speakers. However, when talking about mathematics homework specifically, the K-speakers replied that they spent about 60 minutes twice a week on average, while the E-speakers reported that they spent less than 30 minutes three times a week. The E-speakers seem to be more engaged in homework for several subjects, 58 in addition to mathematics. The frequency of mathematics homework (three times per week in E-speakers’ responses and twice per week in K-speakers’ responses) seems to be related to the number of times class meets per week. As for extra lessons in mathematics that were not a part of regular class, the K- speakers said that they have almost never had extra lessons or tutoring (see question 19 in Table 4.9). In contrast, 37.1% of the E-speakers reported that they had extra lessons or tutoring more than “sometimes.” In fact, some E-speakers said that they received extra lessons from the Mathematics Learning Center (MLC) offered by the Department of Mathematics at MSU]. The MLC is staffed primarily by teaching assistants and is open approximately 40 hours per week for students in lower level mathematics courses. In terms of students’ descriptions of how they study calculus in their typical week, K- speakers’ and E-speakers’ responses could be interpreted as an indication that for K- speakers, learning was more central in their lives because they reported systematically devoting more time to it, compared with E-speakers. Regarding students’ activities before or after school, the E-speakers reported that they were more involved in the out-of-school activities given in the survey than the K- speakers. The K-speakers may have spent time on other out-of-school activities which were not listed in the survey examples, such as departmental activities and club activities, as shown in two K-interviewees’ explanationsz. ’ Some interviewees, who said that they had extra lessons or tutoring “sometimes,” were asked how they studied Calculus in a typical week via email. Two E-interviewees responded to the email. According to their responses, they used the MLC for extra lessons and tutoring. 2 All Korean and E—interviewees were asked to describe their typical weekday via email. Two K- interviewees answered the question. One Korean interviewee responded that she participated in many activities of her department. The other Korean interviewee reported that he did club activities afier classes. 59 Attitudes toward Mathematics Students’ views of themselves as mathematics learners Another potential important component of background is in the area of students’ views of themselves as mathematics learners and their attitudes about mathematics learning. Six items on the written survey addressed these issues. To investigate whether or not there was a statistically significant difference between the K-speakers and E— speakers in their attitudes toward mathematics learning, an independent samples t-test was employed. Each item was scored 4 = ‘agree a lot,’ 3 = ‘agree a little,’ 2 = ‘disagree a little,’ and l = ‘disagree a lot.’ The higher the mean scores are, the more strongly each group agrees with statements in the attitude items. Table 4.13 presents the descriptive statistics and t-test results of the survey participants’ response to each item. K-speakers had a significantly lower score (that is, bigger than 2.5) on item 15-a than the E-speakers, which indicates that the E-speakers expressed a stronger agreement with the statement that they usually do well in mathematics because a 2.5 indicates a neutral response. Item 15-e reveals that the K-speakers had a significantly higher score (that is, less than 2.5) than the E-speakers, indicating that the E-speakers had a stronger disagreement on the statement that “mathematics is not one of my strengths” than the K- speakers. In other words, the E-speakers were more likely that the K-speakers to claim that mathematics is one of their strengths. The K-speakers had a significantly lower score (less than 2.5) than the E-speakers in item' 15-d. In other words, the K-speakers had a stronger disagreement than E-speakers with the statement that when they do not understand a new topic initially then they will never understand it, suggesting that they believe that they can eventually understand a topic that is difficult initially. 60 Table 4.13 Students’ views of themselves as mathematics learners and the t-test results of the comparison of percentage of the Korean and E-speakers’ responses 15. How much do you agree with these Agree Agree a Disagree Disagree M SD Sig statements about learning mathematics? a lot little a little a lot ' . . K 10.3 61.1 23.8 4.8 2.77 .70 * 15-a. I usually do well in mathematics. E 53.0 40.2 6.1 0.8 3.45 . 65 .00 15-b. I would like to take more K 20.6 44.4 27.8 7.1 2.79 .85 91 mathematics in school. 7 E 26.5 40.2 17.4 15.9 2.77 1.01 ' 15-c. Mathematics is more difficult for me K 4.8 23.0 54.8 17.5 2.15 .76 29 than for many of my classmates. E 5.3 21.2 46.2 27.3 2.05 .84 ' 15-d. When 1 do not initially understand a K 1.6 6.4 24.6 67.5 1.42 .69 new topic in mathematics, I know that I will .00* never really understand it E 2.3 16.7 36.4 44.7 1.77 .81 15-e. Mathematics is not one of my K 8.7 29.4 44.4 17.5 2.29 .86 00* strerlgths. E 6.8 13.6 38.6 40.9 1.86 .90 ' . . . . K 7.9 60.3 28.6 3.2 2.73 .65 15-f. I learn things quickly in mathematics. E 18.2 53.8 23.5 4. 6 2.86 .7 6 .15 Note. K = K-speakers; E = E-speakers; M = mean; SD = standard deviation; Sig. = significance level. *Differences are significant (p _<_ .01). The role of mathematics in students ' lives Five items were included to examine students’ sense of the role of mathematics in their lives. These were scored on the scale 1, 2, 3, and 4 (1 = ‘disagree a lot,’ 2 = ‘disagree a little,’ 3 = ‘agree a little,’ and 4 = ‘agree a lot’). In order to check for group differences between the K-speakers and E-speakers in their view of the role of mathematics in their lives, the statistical significance of the mean difference was determined by an independent samples t-test. The descriptive statistics and t-test results are summarized in Table 4.14. Overall mean scores of both the K-speakers and E-speakers in the five attitude items were higher than a neutral response (that is a 2.5). More than 60% of both the E-speakers and K-speakers agreed with the statements in the five items regarding the need of mathematics in their lives. These descriptive statistics imply that students agreed on the need for mathematics. However, as shown in items 16-a and 16-b, the E-speakers had a significantly stronger agreement on the need for mathematics in their daily lives as well as for other school subjects than the K-speakers. There was also a significant difference 61 between the two groups in the mean scores of item 16-c, which indicates that the K- speakers were more convinced about the role of mathematics to get into the university of their choice. Table 4.14 The role of mathematics in students’ lives and the t-test results of the comparison of percentage of the Korean and E-speakers’ responses 16. How much do you agree with these Agree Agree a Disagree Disagree M SD Si statements about mathematics? a lot little a little a lot g. 16-a. I think learning mathematics will K 18.3 47.6 25.4 8.7 2.75 .86 002,, help me in my daily life. E 34.1 47.0 12.9 6.1 3.09 .84 ' 16—b. I need mathematics to learn other K 37.3 33.3 21.4 7.9 3.00 .96 01,, school subjects. E 43.9 43.2 9.8 3.0 3.28 .77 ' 16-c. I need to do well in mathematics to K 77.0 20.6 0.8 1.6 3.73 .56 000,, get into the university of my choice. B 46.2 41.7 9.8 1.5 3.34 .72 ' 16-d. 1 would like ajob that involved K 23.0 36.5 33.3 7.1 2.75 .89 92 using mathematics. E 25.8 38.6 22.0 13.6 2.77 .99 ' l6-e. I need to do well in mathematics to K 43.7 36.5 15.9 4.0 3.20 .85 36 get the job I want. E 40.9 33.3 20.5 5.3 3.10 .91 ' Note. K = K-speakers; E = E-speakers; M = mean; SD = standard deviation; Sig. = significance level. *Differences are significant (p S .01). Summary The E-speakers in this study showed more confidence in their capability of leaming mathematics than the K-speakers. As for the need of mathematics, there was’a significant difference between the E-group and K-group. The E-speakers agreed more with the practical need for mathematics in their daily lives, whereas the K-speakers showed a stronger agreement on the need for mathematics to get into the university of their choice. Comparability of the E-group and K-group Similarities and differences between the E—group and K—group Background analyses showed similarities and differences between the K-group and E-group in terms of their past experience with infinity and limit, current mathematics learning, and attitudes toward learning mathematics. In students’ past mathematics learning regarding infinity and limit, the K-speakers seemed to have had more opportunities to learn concepts related to infinity and limit in high school than the E- 62 speakers. In addition, the grades in which students first heard the word limit were less varied in the K-group. However, there was no significant difference between the E-group and K-group in the range of grades in relation to first hearing infinity. In students’ present mathematics learning, the E-speakers reported that they were more involved in out-of-school activities and they devoted less time to learning, compared with the K-speakers. Data from the follow-up questionnaire suggested that for K-speakers learning was more important, and thus they systematically devoted more time to it. In students’ attitudes toward learning mathematics, the E-speakers showed more confidence in learning mathematics than the K-speakers. As for the role of mathematics in students’ lives, the E-speakers had more focused on its application to their daily lives and other school subjects than the K-speakers. However, there was no statistically significant difference between the E-group and K-group in their perceived need of mathematics for their jobs. Summary The primary purpose of this study is to examine potential differences in mathematical discourse between E-speakers and K-speakers. However, any differences that might emerge would need to be understood and interpreted with understanding of the differences in students’ background that may contribute to those differences in mathematical discourse. While analysing students’ discourses on infinity and limit, all these differences in the background analyses should be kept in mind as possible attributions for observed differences in mathematical discourses on infinity and limit. 63 Students’ Discourse about Infinity and Limit In this section, I shall identify primary features of the participants’ colloquial and mathematical discourses on infinity and limit. These features were drawn from two analyses. The first analysis is based on the paired interview data of 20 representatives within each linguistically distinct group. The other is an analysis of all the participants’ written responses (n=25 8) to the discourse questions in each item in the survey. Differences in characteristics of the Korean speaking group (K-group) and the English speaking group (E-group) were identified on the basis of the paired interview results, and then with the help of chi-square analysis applied to the responses to the written questionnaire, it was checked whether the finding could be generalized, that is, whether the differences were statistically significant. In reporting the data from paired interviews, the following symbolization was introduced. To refer to interviewee members within the E-group and K-group, the symbols such as K6a and K6b were used for the first pair of the K-interviewees who used the Korean 6th textbook in the survey. The symbols of Eoc and Eod represent the second pair of the E-interviewees who used other textbooks. The first characters K and E represent the Korean and English speakers respectively. The second characters 6 and 0 mean the Korean 6th textbook and other English textbooks respectively. The last characters a and b in K6a and K6b represent the first pair of the K-speakers who used the Korean 6th textbook, whereas the characters c and d in Eoc and Eod refer to the second pair of the E-speakers who used other English textbooks. This section is divided into two main subsections: 2.1 Discourse on infinity and 2.2 Discourse on limit. Each subsection presents the properties of the given discourse as 64 reflected in the responses to the relevant items in the questionnaire. Each subsection closes with a summary of characteristics of colloquial and mathematical discourses on infinity and limit respectively. Discourse on Infinity Items 1 and IX 65 :0 0.05—52% 0 z 2235.... 25:5 5.: 2 m .0555: 0 .0: 0.5:: . .0550. .56. jaaj :02 055.5: 0500050.. :05? :30: :02 055.5: 0: 00:50.5 50 > EN: 0E¥ :02 .5 20:55: 05:5. 7.: 20m 2o 02. 25 25:: 0:55 2: an as. :02 00m .5 550:5 055.5 :0 0.0.0:... 7.: :02 5.305050.— 0::c5 0.0: 05 H 33 :02 :0 50.0 5 55M :02 5550500 0: :00 50» 5:: $53 .20 vom |ll:02 0.0 555 055.5 :0 0:05 53 _ hm 0:505 0:0 08:003. 055.5: Wm: 05! ..0555: 05:5 :0 05 0205:. R: 00m 055.5: 0: :EM :0505 0:5 :02 5:520: 055.55 00: _ $3 :02 55—5500 000:3 550 0 m_ 0: 7.3 :52 05 20325 055.5: 0.5 020:... I 3 00m 82 558 22:... “In: Sz :92an 25555: 2: 33:5: Em :02 20:_5.::550|>10.::u5 :02 30:00 055.5. 5 50:00. 53 _ EN: :52 :0 550:5 055.5. :0 m 020:5. 8: 05m .20 5050.50 .3 5550500 00 $2 . . . 00v. . . . w 0050550 03. 055.5: 2 8:050:55 :53 :nm :02 :02 :02 0.203050 2 205:5: 05:5 :< Tun 05:55 @5055 0>= 03 ES 03— w::005 20050 .5 20:55: 0: ._. ”a 0mm :02 05. 055.5 .0505 :8: 50:05 300502002055511 sl....l.l._...0~l_:mx:0:5 bmmwwlmwmlrg- 0:55:00 :0 55050 :0m :02 :53 50:00: 0: 05 503 _. Hum: 05:5 2 55050500: 2: :05 :52 0:5 5 :0 0>0: 20.50520: 7: 00m . :52 2030: 20:55: :05; 5 20:55: 00M . .2 . . a 5 .2580 05:5 5. a: 00:05: 350-50: .00 0 :05 0:05 0: m_ :50 :3: 0:00 .50 55:» 0mm :02 :02 . :02 .002: 055.5: 00: 5:000: >2 2 m: 0:: 0203:: 05:5 0:: 5 E: 03. :0 550:5 055.5 :0 2 0:05. E 03 000% 5050: 05.5.5: :3: :52 05:55 0: 550:3 0:... 8: :nm :02 :02 . . llllilillilllli1311:1111 055.5 :0 0:505 555% E0 _ 82 :0 2 0:05 :0000 0:: 2.0.6.5. F: 0.3— :52 20:55: 055.5: 0.5 020:... RH 03: 52:20.5 .«0 :55 0: :02 0 2 555—5050 55550. 055.5— 8m: :53 :NM :02 20:0 :05: 55.: 7; 50m 11:11:11 00.18555 .52 5.5.8855. 5:: 5; . . .552, o :5 2 2 0050558 055.5 .20 550 0:._. gm: NM :5 2 m: m05_0> a .50 20:55: 0: 5. mm: 0m 50.0.5: 5:558 :00 0: m 0.5 2:050 :02 :0m _0 .20 20:55: : U: .5 20:55: 05:55 :0 30:05. HS :52 :52 055.5: 0: 8 5000 20:552 W: 1111 055.5: 0.0: < .50 .00 0F: Pm: EM 2055: £02 0vm .5 550:5 055.5 :0 0.0.0:: E 50500 00:0 00.. 50500 00:0 00: 50500 00:0mm0m 5020.55.25 5606:55— 00032205-! M0555— 000303.855 3058 3055.5— 52:00.55: 055.5: 0:03 530:8 05 :53 00:050.: 0 050.5 .03 .50 _ 02 0:0 5 250: 5 055.505 203 05 9505 0050500: 30:50:: .50 555m 26 030:. 66 :00: 05 00500 :0 0: 50:50:00 :02 0:55.: :02 005050505 :0 50:55:00 0:: :HM :02 w50:0-:0>0: 00.: M5050 0.: ”no: :9: 0.: 550.50 020» 5 >2 0:. .2055 >005 5. 0:5 5 w:0_.:< we 0 M :02 5: 5 :000: :0>0: :00 50> _vw_ 00m _ . : . : . : 500:3— 5 0 5:50 50 0 00: :05. :2. 5:5 82 05:5: 5.5.: 0: €0.02: 82 mfimmawhfiwfifimfiwmwomxw mm: 5.2 2 800 x 0.. :55: 0 0s: :00: 00.: >.: 00:25.0 2:05.: :0: : .. . 5 __ : S 0: .iimolz - .305: 5000:: 25 0.: .02 80 . .2... .........M.......:...... _. ...-....... . : 2 m5.w:w::_”:.::05::_0:ww: 005 :W RD. 2 .m=00m.002v 0:55.: 0.: 000: Go: 052 5 2 A 555:5 05000550 .0 0< :2 00m :02 cats: 98 tad—:ofioc: “—0 o_ :0>u:o.w :02 0:55.: 0.: 002m 0.555: H0: €05.M=00M.000<: 050$: :0: We: :5— :52 :0 0w...b_::.:5 05:00: 0: 55:5 ”mm :02 0:55.: 0.: 555000: :00: 0 5: 0>_:0w0: 50:: 050: 0:05:52 82 mm :0 00555000: 0 ~00-0:.000-002v 055?: 00 0:0 2 0:55.: 05: 0.500.: Ft 5 2 20:55: 5:55: 0:0 0:0w0::_ 7.0: 00v— :02 00000:: :B 30-05.5030 M50:0-:0>0: 0 :050 05.00.:— EE 0mm :02 0:55.: 0.: 002m 0.0—500: 7.2 :02 .0005 0:55.: 000 05:50:05 :50 HS: 002 ... 55%.:..fimmfiwmfi .3. ..z 2......mfimwmfifi a. .5... :52 55:5 0: 55550 00:0550w RE :0 00% 505.58% 0 0:00 0: x :0>0 0:0 :0 35:5 55:5 2 .002: 0:55.. :0 :0: 50:5 _ 80: 00v: 5 2 05000550 x 00 :5: 0: :. FE 00m 0550: 0: :0::00 :0:: 550500 A .52 2.0%.. .0 85:05:20: 55 :0: 0oz 0.0 00:02.... uwdwmhfimm ”MW: {£211-1510mfico0 0;: @155 :0: 00: . :02 35:5 0004—000 55:01an 00M 0:0 :5 :3: 5:: 0: 00: :_ 005000: :3 :02 0:55.: 0:0 005.5000: 50 ED :02 : .0500: .255 30:55.: w:0E< $3 03: :52 55:5 0: 000w 5505: 0: :. :03 0mm :02 :0>0:0: :00 505-505.0005 0:55.: . :NM 000m 00050 :0 0:5: 55:05: RE 00m 502 :0 0: 20:55: :0 :0 :00 0::. Hot :02 03005 5.5:: 30:55.: 0:0 0:0::. :3 09. 0 3150 0100: 5 2 :05. 5:00:55 05000550 0. ENE 00m :00 :0::5: 0 :00: :0: :52 50-505002: 0:55.: 0.: 05050.0 :02 000-00 : A 0::MMWUM5h ”“05 M00.“ :0:—v: 1.. EH 0.: .bIficE 0: 000m 5502 :0: :0”: :o .32.... .0500... 2:: :00: 5. : . . a: 00 :0: 82 55:: :o: :0 ow 5:8 05:. .01 2.0 50500 00:0 00: 50500 00:0m00: 50500 00:0m00m 5020:0555 __000_:£:_.::_ 955:5 000322256. 00030555-”: 0:03 530:0: 0:: :53 050500 0 050:0 .5 0:0 _ X: 0:0 : 050:: 5 .955: 0:03 05 @505 00050500: 305.55: :0 b00556 0 : .0 030:. 67 Table 4.17 Distribution of the contexts of use of the word infinite and the chi-square results of the comparison of difference between the Eggrog) and K-group Non-mathematical Mathematical Chi-square Students Words context context None df Value Sig. E-interviewees (n = 20) Infinite}; 45 % 55 % 0 % ' 85 °/ 15 °/ 0 °/ K-interviewees (n = 20) InfiniteKcOn o o o InfiniteKMath 65 °/o IS % 20 °/o E-participants (n = 132) Infinite}; 34.1 % 52.3 % 13.6 % l 55 69 000* K- artici ants (n =126) InfiniteKcon 81.7 % 12.7 % 5.6 % . ' p p InfiniteKMmjI 36.5 % 38.9 % 24.6 % 1 1.69 .19 *Differences are significant (p S .01). A. Infinite and infinitely: the type of discourse. E-speakers used the adjective, but not the adverb. The use was mainly in non-mathematical discourse. K-speakers used both the adjective and the adverb. They used the adverb when they were asked to create a sentence with the noun infinity (either mathematical or colloquial). Their uses of infinitely and infinite was mainly in non-mathematical context (even more so than in the E-group). The E-interviewees used the adjective predominantly in non-mathematical contexts ([2], [4], [7], [9], [12], [13], and [14]; 7 responses out of 14 in Table 4.15). Among the K- interviewees, the use of mathematical contexts was rare even for the mathematical version of the word infinite (2 responses out of 12 for infiniteKCou and 2 out of 13 for infiniteKMau| in Table 4.15). The chi-square results in Table 4.17 show that the distribution of the word use of the E-participants and K-participants in the survey between mathematical and non-mathematical contexts is significantly different when the word infinite is colloquial (x2 = 55.69, p = .000), but not significantly different when the word is mathematical (x2 = 1.69, p > .01). Table 4.18 Distribution of types of entities described with the word infinite Students amount or number of something self-sustained entities Chi-square described as infinite described by infinite 4f Value Sig_._ E-interviewees (n = 20) 6O % lO % K-interviewees (n = 20) 5 % 60 % E-participants (n = 132) 30.3 % 9.9 % 1 67 94 000* Kjarticipants (n = 126) 0.8 % 48.4 % ' ' 68 Table 4.19 Distribution of the use of the word infinitely as a descriptor of many Chi-square Students Infinitely as a descriptor of many (if Value Si . E-interviewees (n = 20) 0 % K-interviewees (n = 20) 6O % B—participants (n = 132) 0 % .4 . * K-participants (n =126) 37.3 % l 60 1 000 *Differences are significant (p S .01). B. Infinite and infinitely: the type of use (meaning). E-speakers’ use of the adjective was in the context of large sets. In their sentences, the adjective infinite appeared in the expressions “infinite number of” or “infinite amount of,” that is, as a descriptor of a size of a set. K-speakers used the adjective infinite as descriptors of concrete things known for their large dimensions or of spiritual matters. They used the adverb infinitely as a descriptor of many, in the context of sets. The majority of E—interviewees used infinite as descriptors of amount of or number of elements in a set such as grains of sand and stars (see [1], [2], [7-8], [10], and [12-14] in Table 4.15). The set was thus treated as one entity. The majority of K-interviewees, with just one exception ([27]), applied the adjective infinite, either in its colloquial or mathematical version, directly to self-sustained entities (concrete objects: sea ocean, seashore, earth, and universe — 5 out of 12 responses; spiritual matters: sorrow, love, complains, possibilities, and potentialities in Table 4.15). Only K-interviewees used the adverb, and they did it when asked to use the noun infinityKCon (they added the suffix of hee to infinitchOn which turned the noun infinity into the adverb infinitely). They used it as a descriptor of “many” (see [56-59] and [67-68]). These phenomena were clearly seen also in the written questionnaire. According to the chi—square results in Table 4.18, there is a significant difference between the E-group and K-group in the percentage of sentences in which the word infinite is used as describing entities. Chi-square analysis in 69 Table 4.19 indicates a significant difference between these two groups (x2 = 60.41 , p = .000) in the use of infinitely to describe many. Table 4.20 Distribution of sentences not using the noun infinity . . . Chi-square Students Sentences not usmg the noun mfimty df Value SiL E-interviewees (n = 20) 0 % K-interviewees (n = 20) 95 % E-participants (n = 132) 0 % 1 179.91 .000"‘ K-participants (n =126) 77.8 % *Difi‘erences are significant (p S .01). Table 4.21 Distribution of the use of infinity as process Infinity is unreachable and unpassable end-point of Chi-smiare Students . . never-ending process ay Value Sig. E-interviewees (n = 20) 45 % K-interviewees (n = 20) 0 % E-participants (n = 132) 15.2 % 1 17.86 .000“ K-participants (n =126) , 0.8 % *Differences are significant (p S .01). C. Infinity. E-speakers’ use of the word infinity was in association with processes, which were said to be never ending. The infinity itself was said to be unreachable or impassable. There was no association of infinity with largeness. K-speakers did not use the noun infinity, either in its colloquial or mathematical version. When asked to construct a sentence with the infinityKMa,;,, they converted the noun into adjective (infinite) and when asked to construct a sentence with the infinityKCou, they converted the noun into adverb (infinitely). Only one E-interviewee gave a fully structural response that described infinity as a number ([52]). Others were talking about it in the context of something in an unending ,9 ‘6 process (see the use of verbs “go on/to,” “pass, reach,” and “approach” - 14 out of 16 responses in Table 4.16). None of the K-interviewees’ responses contained any of these verbs. The single response of a K—interviewee that did contain the noun infinity featured the verb diverge (in the expression “sequence diverges to infinity” [73]). For some E- 70 interviewees, infinity was tantamount to a never-ending process ([49], [55]). For others, it was an object that was an inextricable part of a process. This object was applied predominantly in the sense of an unreachable endpoint of processes that do not end. The word infinity appeared in some other object (x, fimction, and numbers) that goes to infinity (in an expression such as “x approaches infinity” [42]). Table 4.20 shows that about 78 % of the K-participants used other grammatical forms to create a sentence rather than using the noun. In contrast, the only grammatical forms employed by the E- participants were nouns. A chi-square test in Table 4.21 indicated that the E-participants were significantly more likely to report having used the word infinity as an unreachable and unpassable end-point. Item 11 Table 4.22 Distribution of endorsed narratives for comparing pairs of two sets in item 11 . Endorsed narratives Chi-square Comparisons Students A = B A > B A < B Can’t Cy Value Sig._ E-interviewees 25 % 10 % 60 % 5 % 11-3: Fingers (A) K-interviewees 60 % 40 % 0 % 0 % and toes (B) E-participants 39.4 % 14.4 % 38.6 % o % 2 47 94 000, K-participants 56.3 % 28.6 % 3.2 % 0 % ' ' E-interviewees 45 % 25 % 25 % 0 % II-b: Odd (A) and K-interviewees 30 % 15 % 30 % 20 % even numbers (3) E-participants 41.7 % 17.4 % 22.0 % 9.1 % 3 I3 53 004' K-participants 21.4 % 20.6 % 19.8 % 19.8 % ' ' 132-interviewees 10 % 10 % 80 % 0 % 21:25:?‘32‘23'5 K-interviewees 5 % 5 % 7o % 20 % (3) g E-participants 15.2 % 8.3 % 61.4 % 3.8 % 3 15 61 001: K-participants 6.4 % 1.6 % 73.0 % 10.3 % ' ' Note. “A=B” = A is the same as B; “A>B” = A has more than B; “A B. Only half as many K-speakers chose the canonical option A = B. Other responses were distributed evenly between A < B, A > B, and “can’t say”. Some E-speakers (17.4 %) and K-speakers (20.6 %) determined that there were more odd numbers because counting started at one. Other E-speakers (22.0 %) and K-speakers (19.8 %) concluded that there were more even numbers because zero as a starting number was an even number. However, only K-speakers (19.8 %) replied that even numbers could not be compared with odd numbers because they were both infinite and countless. F. II-c: A = odds and B = integers. Only 10%-15% of E-speakers chose the canonical response A = B. An overwhelming majority (80% in the interview and 61.4% in the survey) chose the option A < B. The percentage of K-speakers who chose the canonical response A = B was even smaller than that of E-speakers (5% in the interview and 6.4% in the survey). Approximately 70% chose the option A < B. 72 Table 4.23 Comparisons between figers and toes in item II-a 11. Of which are there more? (a) A: Your fingers, B: Your toes 54a [1] Toes. 1 don’t count thumbs as a fingerm Kla [17] They are the same because fingers are E4b [2] Neither. 1 don’t know if you can do Klb 10 and toes are 10 and the cardinal numbers that are decided exactly E4c [3] T968 because thumbs aren t part K2a [18] Same because of ten and ten technically fingers E4d [4] Fingers because they’re longer and K2b [19] Fingers because fingers are more there’s more mass to your finger sensitive 85a [5] Fingers because they’re longer K3a [20] Fingers because fingers are used more E5b [6] Numerically they’re the same K3b [121] F mgers have senses and can move on err own E5c [7] There are more toes because 112:: [3%] game. ' '31:): agenaturaldmémbers E5d technically thumbs aren’t fingers E11036 rom w a '5 mg use ’ mgers are E6a [8] Toes...you only have eight fingers and K6a [24] They are the same.. .the numbers to be E6b ten toes K6b seen are the same 57a [9] Your toes because thumb doesn’t count K6c [25] Fingers are used more than toes E7b [10] There are exactly as many fingers or K6d [26] They are both 10 and 10, so they are toes so there’s neither more the same E7c [l 1] Toes...Because thumbs don’t count K7a [27] I counted them so that they were the 57d K7b same :0: [3] ram: Snag ttl’tem arebmore Kma [28] Same...each of them is 10...because o [ ] c ec e oxes. .. ecause you Kmb they are finite have an equal number Eoc [14] Toes, because thumbs aren’t fingers ch [29] We use fingers much more...there are , more fingers Eod [15] Neither...ten fingers and ten toes Kmd [30] Fingers are ten and toes are ten Kme [31] Their cardinal numbers are the Eoc , same...there are 10 and 10 Eof [l6] Toes. . .because thumbs don t count Km f [32] Fingers are more highly valued in utilization 73 50.55:: :3 00:0. . 535:: ::o 50:... 0::5 3 :8 535:: :0>0 05:03 535:: ::O :3 111135555355 .5358 :05 0:50: 0: 255% :0: 5.: 8: 03:05 5: 0: :05: 500 ::: 50:05: 0:: 55 55:3. 05:03 55038 025—05 :: 5: 95:05:... 05 0: 0: 500m :3... RE :EM 052 :3:5: :0>0 :: 3 0: 0:0: 5258 2:00: 058 .5: .:0 ::: :0 80w : 00 0:35:50 5:05: 3:55:03505 50:05: 0.5:. :2 :0 :mawmmmgw .m::_.:m_:m.m:80mi.m_.:x::.~w5: _:mmw|%:w._::d.wmo5 mwmmflw 31w..- :0>0 05530500 055 :0::5 ::5 0.0. o 53: :0 5.: _ . :55 o: 0 :0m 0.0m :52 30:35:: :0 5:05: 0:5.5: :: 0>3 :0» 0583 H058: 55:02 SE :9: liltmi:.0..:5:: «0.313155le :0 ::5 0:15.: 15m: afiflwwamflmwww. .--ililul: 11111 magwxmmwdmluMMmmflfiflumflmsmSmflufiafl.mm: 0583 :05 .N 3 535:: ::o 3:555 03 .: 53:5: :0>m 33 05M t. . .50 55» :03...:0>0 : o 05:03 535:: :0>0 0:05 m.0:3._. 5E 05:: 0:: 55:00 03 :58 535:: _::_::8 05 .0:0-0:-0:0 .3 38858 03 0580m 2.8 95v— :0» 00.: 0:55. 0:.»05 0583 53 :0 :35:: 05:: 05 90:35 FE pom 0flfimmflmmnwamflmmmwflamfl i-.-il.--mwmete..owemmmmmmamm.wwmmwmmnqmmutaammmlammmfl.EWMMMWM ...:35:: _::_::8 05 5:8 5:58 03 6:55 0.: .2 GE :52 _ 5:...— 5: 5:3 5:2: 5:58 0583 535:: ::0 05:3 _ GE :0m 0.59.85: 535:: _::_:::0 :0 :0m_:::500:.0:::.::_ 0:.»35 We: :5. :35:: ::o :: : 0:0 ::: 0:0 :: :8: :0» 05:03 535:: ::0 FE ::m ..... mmwflm www15::l::4m_.ammmmw_.0!a ”matmmxaqnmwwMEflmwMMWwwflawfl. :3: .35 MammydtxmmmmHrammzmmx£§wflma wwfiammmmmmmmmdmfl- 0mm :35:: :0>0 : :035: 05 .o 550:: 55 05:0 05 ::0: 0: m :55: :...:0 2 0:05 .: 05:: 05 0: :...E0::: :5 5 :0>0 .::0 .:0>0 .::O :3 :3: :8 :5: 3:8. .50: : :_ :35:: 35.5: ::20583 .5562 RE 35m ........ :1 magi. H$wiwwjflmam0mmmmmwmmmwtm 1:1..mm0flww—lflmug. 03: --...wmalmmm1:.w|:mfltwtnwwwEflydmmmwmwnwmfiwwmqfiwwwdfluammmmfllmwfl. ::m :050 05 ::5 0:05 :0>0 0:05 0:0....0:0N w:_::_0:_ 0:50» .: ...:0>0 :: : 0:05 :35:: .0: 0:0 ::5 >8 558 03 .555 0:5.5: 5:8 558 03 :3 nov— ::0 bo>0 5:3: :05: 00500 ::5 :35:: ::o :: 2 0:05 :35:: ::m 535:: :0>0 5 8:23: 3 0: :58: 9.5355 :0>m SE :3: :0>0 bo>0 5:...555 0: cm 535:: :0>0 ::: 535:: ::O :E ::m 058:.— _:: 0 _-:m :0>0 :N .055 05 . 5.5: 0: :00 : m< $2 :3. ::0 0:05 :0 5.55: 05:m...0:0 5:3 :50 :0 058. 535:: ::O 0: 0:3 _ :mmwflmflmwmdmmmmmflmflwmfi. 0005500 0:: >05 0583 035::585 0:: >35 83 :3: :0:—:0: 52:35:: :0>0 :: 53 0:0: 3505 : 058. :0>0 :_:m _ 32 0mm :0>0 :: : 3:5 ::: 0:0 ::: :8 :% .:35:: ::o :: 0: 0:05 :55: 0: m0: : 00:: t 535:: 803585 0:03 535:: ::o...:0>0 :00—030 _ PE :3: 0:: :35:: 0.33 05 :0 5355 0:3 _ 0583 05:: 05 0:53.: Sm: :3 055 3 0: 500m wwflycmmmmvdxnwmmwiafi mi:.0>0 055 3 :mmgmmwmmnqmmammfiwfim ::0 55:3 53:5: ::0 ::: :0>0 53 0:: 0:05 0580m $2 :3: :: m.0:0~ mm0_::...:0>0 0:53.73 ::: N :5: T :5: _ 0:: 0:3... Fm: :mm .9205 : 5:: =3: :50: :5: 5:3 0:3 0:0 :2 05:0 05 P055 :55 _ .0m .: _: :0: 5:5 5: 535:: :0>0 0583...: 50:: :50 535:: 05:03 055 0:: 535:: ::0 $3 :9— 055...0m :5 535:: 05:: 05:3 : 05:505.: 5:: t8: :0 > 32 ::m «lwfimwmmmmwmflME?::Bgmaflflwflmmmmgmmufimmefl :9: -ill.x$35451:melawmamwdgmmfltmgmwmwmgfilm... 3.: 535:: 5:53.523 : P: 05:03 05:0 05 0:: 85:05:55 55 05:0 05 .5 :50— :fi 0.5.0:: 0:05 ::5 B3 :0 028 0:: 535:: 55:50 05 5:55: 0: _+0_N 3: :N ::0: _ t 32 EM :0m : 0x: :0: 90:05 05835535: 05 5:3 w5.ow :03 :0» .: Fm: new 2 0: : 50.: 5:8 03 .: 05835058 0:: >35 :2 :5magma:mfiNmflMmflmwwm—Immmmmwmmmmmqumflmmmmw. 2M :9“ 05:: 05 P: :55 _ 0:0: 5:00 :0» .5 3:0 535:: :0>m :2 ::m 53:5: :0>m ”m .535: ::C u< 520:.— 0.55 0.8 £0_£>> .wo .= e: 82: a: £35.: :0>0 5: ::o 55:: :55: :8 v3 03:: 74 . 50 0:5...:0 ::. m. :00 05 50:50:. 5 :00 055::0 05 .::0.:::0:0 :: 5805: 50m :00::0:: 3: 55.3 0.5m :33 40.5.5. 5.3 555 0:::500 0: 0.550: :0: 0.: :8: :5v. :0: :3: m8 :.::0 3.8: :0» 6:55 .::0 :0 ::0 0: :: 535:: 58 :05 :om ilQMEQEasfinfimo :0: P: .0:dwd.lm.:wl5§m:x ::m 508:5 :0 :00 3: 055. 85.05 0:: 535:: ::o. . 508:5 Pm. 00m. 0583;033:3858 0:90:05 05003 :3: 05:00».— Hmo : 05v: 535:: ..: 0::.05 :5m 508:5 0583 5085. Gm. :0m :5v_ ............................ I ..................... 535:: ::0 0::.05 508:5 05:03 5085. H 5: 05V: 0500 0 :05 03:51? :05 0 :: 5:0.8573: 55085. ::: 535:: ::o :0 :35:: 0:55 :: 0>3 :0» 0583 :0: 0:3 :. F3 00”.: :0 0:52.30 :.: . . 05:00 3:035: 5 0 :30 5:55:05: 55:00:: 0358:. 0:05 0: 0w 0: 8:558 508:5 So: ::: m.:5.0h::w.0:::.:0.:0: 2:03 “:5 05:03 50M5:: ::o 05$. :3". 30m illxl ......... mm: mm.mmm-x.mmflxflmw§u0l:m:.x.m.x0i:u:fl.:m...~m...mm:.....m:.:x.._.m:i DEV: .::0 :0 :0>0 3 5.55 :0 8555 :0 :0.::0..:.:.:5 :0 555 0580m ::o: :5! :8: 0m :35:: 0.33 : :5: m. T085. ::: : 0583:5085. 7m». :0m 0.55.0 5. m. 535:: .:5:::0 :0 :05:::500.:m0::5.:5 03: 0:::500 0: 0.505: :0: :_ 5:. as: :085. :: m. :35:: b0>0 0583:5085. fix. :5 508:5 05:8: 0::.05 508:5 0583 508:5 05$. :3 :5. 05m. 535:: ::o 0::—05 5085. . . 535:: 5.0.550 ::v: 535:: ::0 :0 :::05: 0500:_.>.>..:.3mum:|31.::z.._.:.m0.:.0 0::. : 8.: :3 : 5 535:: ::o :0 :00. 3: 03 3:0 :0: : 05.5.5.5. 850:0: :0 0::: 5. 8w. :5 0:05 5 508:5 :0 :35:: .:5:::0 05 68:: 5wa : 0:: 508:5 :3: 5085 new 05:00m 535:: :0>0 ::: ::0 0:5 :0:.>.: 0:: 5085. 3:. :8: 0.58 535:: :0>0 5.: 535:: ::o 55085. 0:05 0:: 0:3 H 3:. 3m 50 0::. 5 85.05 0:: 535:: ::O :::: 33: 0.35::ammmm 535:: :0>0 ::: ::o 53 0.: 0583 508:5 SE :3. 0:: 535:: .:5:::0...>::5 50:55 0:: 53 0583: :8. :3. 0mm 5085 :0 05:: 00.: 0:: :3: 05:0 ::: o .:0.:::: :. 535:: .:5::: 0:: 535:: :0>0 ::: ::o :8: :3. 05 3 0: 0>3 x3: 00... .00: .5555 0: 0m 53 m3: 05:00m PE 33 ham:mmmamwflwmgwwlwwamflwflflwflmfiflmfl 508:5 55.3 535:: ::0 ::: :0>0 0:: 0:05 0580m :3 . :mM :50: 0:0 00... M055 ::5 :0 05:03 535:: ::0 0:05 0.53... GE :8 25535:: ::0 :0 :0. : 0:: 0:05 N ::: . 50 0:5 :00>>:0m 8:: 39. 5:0 m: a m: 05>»: 0.55. . .:0 0:5 :: m. :35:: 0.33 50>“: FE :vm any: 5 85.05 0:: mug—fig. I--:----..--:xxiliiiliummwmmwflmwzmwam«wwmmlmmnflnflmfiwwmfimwlo. ::o. . .m. ::0 05 0:33 305. :.:0: 03 05:03 5085. ES :9: 5:35 0m :05. . 53:5: 35:5 0:: 0:05 05:03 5085: :::. 0cm. E :0 ::5. 5 7; :0: 0.5 :35:: .:5:::0 3: :0 :.::. :...:0m 05:0 3: :m 0: :3 75:05: 058... :55 0: : 50 00v. 9. 58.: : 0.: 058355355 ::0 0:: 0:05 535:: .555 35: 0:91: 5 00:3: 0%.: 55.35535: .:5::: 0:: 0:05 .5085. 55.3 05:00m $3 :5: 3 P: ::: .555 5: :0 0w .::0» ::5 5805 . 05:03 5085: at ::m 508:5 “m 535:: ::O ”< :0: «055 0:3: 0:: :05? :O .= 0-: 50:: 5 50 0::: ::: 538:: 2:0 50:53 28:5: :80 nmé 03$. 75 Table 4.26 Distribution of phrase-driven and structural uses of infinity Comparisons Students Phrase-driven use Structural use Chi-square . df Value Sig. E-interviewees 55 % 0 °/o Il-b. K-interviewees 5 % 40 % Even and odd numbers - ' ' ° ° . E participants 30.3 /o 0.8 /o 2 73.84 .0001, K-partncnpants 1.6 % 33.3 % E-interviewees 3O % 5 % Il-c. K-interviewees O % 35 % Odd numbers and inte ers - ' ' o o g E participants 29.5 /o 2.3 /o 2 73.98 .000, Kjartlgpants O % 34.] % Note. *Differences are significant (p s .01). G. K-speakers’ discourse on infinite sets appeared more structural than that of E- speakers, notwithstanding the fact that only E-speakers used the noun infinity. K- speakers explicitly referred to sets and to cardinal numbers associated with sets, whereas such reference was practically non-existent in the E-speakers’ responses. The E-speakers’ use of the noun infinity was phrase-driven rather than structural. In other words, the noun infinity appeared in phrases such as “goes [on] to infinity”. Many E-interviewees spoke about infinite sets in items II-b and II-c in terms of processes (“goes to infinity”, “goes on and on”, etc.; see [34-35], [38], [44], [46-51], [72- 74], and [77] in Tables 4.24 and 4.25). Such reference was rare among K-interviewees and when it did appear, it was often formulated in a formal mathematical way (e.g., “I send 2k and 2k+1 to infinity” [53] or “As n goes to infinity...” [59] in Table 4.24). The majority of K-interviewees made reference to cardinal numbers associated with sets (see [53], [65-67], [70], [88], [93], [95], [98], and [103] in Tables 4.24 and 4.25). The chi- square results in Table 4.26 show that the difference between E-respondents and K- respondents found in the interview also appeared in written survey responses. H. Eleven routines for comparing sets were identified in the interviews and the survey: 76 1. Comparing by counting: Some interviewees counted elements in A and elements in B, compared the counting of elements in A with those in B, and then endorsed that A or B had more elements because the counting of elements for the set A or B ended up with a larger number (see [52] in Table 4.24). 2. Comparing that involves treating size of infinite sets as subject to the same rules as that of finite sets (doubling increases, halving makes smaller): The students calculated the number of elements in the given set from some data. For example, the students would state that two sets are equal because they are “halves” of the same infinity. The amount of elements for given infinite sets consists of half parts of the same infinity (see [53] in Table 4.24 and [72], [81], and [88] in Table 4.25). 3. Comparing the numbers of elements in two sets without specifying how the numbers were found. 4. Comparing the size of corresponding elements of the two sets: There were interviewees who created a one-to-one mapping between two sets A and B and checked whether the number of elements of one set was consistently bigger than the counterparts from the other set. If the elements of the set A were bigger than those of B, for instance, they endorsed that A had more, A was bigger, or there were more elements in A (see [62] and [71] in Table 4.24). 5. Comparing the size of corresponding partial sums of the two sets: Other interviewees focused on comparing the magnitude of corresponding partial sums. They interpreted that if the partial sums of one set could be shown to be consistently 77 greater than those of the other set, they endorsed that the set that was greater in partial sums, had more, or was larger (see [8] in Table 4.32). 6. Checking two sets for inclusion of one of them in the other: Some other interviewees checked whether one set was included in the other (e. g. by checking the relative density of the two sets on the number line). If one set included the other, they concluded that the including set had more or was larger (see [40] in Table 4.24 and [94] in Table 4.25). 7. Comparing the numerical range covered by the elements of the sets: The students would deem a set of numbers as ‘bigger’ if it spanned a larger segment of the number line (see [45] in Table 4.24). 8. Constructing one-to-one mapping between the sets: There were interviewees who built a one-to-one mapping between A and B in any way. If there was a mapping from A to B, then they endorsed either that A and B were equal if the mapping was a surjection on B, or that B had more (or B was greater than A) if the mapping was an injection on B (see [67] in Table 4.24). 9. The use of the assumption that any two infinite sets are equal: Some interviewees endorsed that A and B were equal if they saw that both sets were infinite (see [43] in Table 4.24). 10. The use of the assumption that infinite sets are incomparable: Other interviewees endorsed that A and B could not be compared if they saw that both sets were infinite (see [61] in Table 4.24). 11. Non-numerical comparisons (see [19] in Table 4.23). In addition, in several cases we opted for the following categories 78 12. Unidentified routine: This is the case, for example, when the student says that one set has ‘more elements’ than the other. 13. No answer Table 4.27 Distribution of routines in comparison tasks in item 11 E-speakers K-speakers Routine interview Survey interview survey lI-b ll-c Il-b lI-c Il-b II-c II-b II-c 1) Comparing by counting 0 % 0 % 0.8 % 2.3 % 5 % 0 % 2.4 % 2.4 % 2) Comparing that involves treating size of infinite sets as subject to the same rules as 0 % 15 % 0.8 % 7.6 % 5 % 0 % 1.6 % 0.8 % that of finite sets 3) Comparing the number of elements in two sets without speci/ying how the 0 % 0 % 0 % 0 % 0 % 0 % 0 % 0 % numbers were found 4) Comparing the Size of corresponding 0 % 0 % 2.3 % 0 % 20 % O % 7.9 % 0 % elements of the two sets 5) Comparing the Size of corresponding 0 % 0 % 0 % 0 % 0 % 0 % 0 % 0 % partial sums of two sets 6) Checking two sets for mcluszon of one of 0 % 75 % 0 % 50.0 % 0 % 80 % 0 % 67.5 % them in the other 7) Comparing the numerical range covered 40 % 0 % 32.6 % 0 % 25 % 0 % 31.0 % 0 % by the elements of the sets 8) comma“ ””34”“ "’“PPW o % o % 0.8 % o % 10 % o % 9.5 % 4.0 % between the sets 9) Th.“ use Of’he ”WWW” ”W “’9’ ’W" 60 % 10 % 44.7 % 16.7 % 5 % 5 % 1.6 % 2.4 % glimte sets are equal ’0) The “‘9 ”f‘h" “3"“me ’ha’ ’"fim’e o % o % 6.1 % 2.3 % 20 % 15 % 22.2 % 10.3 % sets are incomparable ll) Non-numerical comparisons 0 % O % 1.5 % 0 % 0 % 0 % 3.2 % 0.8 % 12) Unidentified routine 0 % 0 % 3.8 % 9.9 % 0 % 0 % 6.4 % 3.2 % L3)Noanswer 0% 0% 9.1% 11.4% 0% 0% 14.3% 8.7% I. In comparing A = odds and B = evens (II-b), E-speakers tended to claim that two infinite sets are always equal (routine 9, 44%). Only very few K-speakers used routine 9 (5% and 1.6% in the interview and in the survey, respectively). They relied more strongly than E-speakers on the endorsed narratives that infinite sets cannot be compared (routine 10; 22.2% for K-speakers versus 6.1% for E-speakers). This is due to the fact that the Korean word for infinity was countless, that is, “which cannot be counted,” and the Korean participants simply derived that what cannot be counted cannot be compared. 79 EEC [v ' :2" J. In comparing A = odds and B = integers (II-c), both groups relied strongly on the endorsed narrative “proper subset is smaller/has less elements than the whole set” (or “infinite set that includes ‘half as much elements’ as another infinite set is smaller) (routine 6; E-speakers: 50% and K-speakers: 67%) Table 4.28 Distribution of contradictory answers in items II-b and II-c Item E-s eakers K-s akers II—b: odds (A) and even (B) lI-c: odds (A) and integers (B) p pe Answer Routine Answer Routine Interview survey Interview survey Equal 2 A is smaller 6 0 % 0 % 5 % 1.6 % Equal 8 A is smaller 6 0 % 0 % 5 % 4.0 % Equal 9 A is smaller 6 40 % 26.5 % 10 % 7.9 % Incomparable 10 A is smaller 6 0 % 1.5 % 10 % 11.1 % K. In items II-b and II-c, there were respondents who produced two contradictory answers. The contradiction was usually the result of the fact that the respondent endorsed two narratives: 1) If A is included in B then A is smaller and 2) If A and B are infinite then they are equal (or cannot be compared). This contradiction appeared as the result of applying two different routines of comparison. The respondents’ routines are presented in Table 4.28. The following Episodes 1 and 2 are excerpts from the conversations with an English speaking pair (E-pair) and a Korean speaking pair (K-pair) respectively in comparing even numbers with odd numbers and odd numbers with integers (see Appendix E for the Korean original conversation). These two episodes exemplify two contradictory answers, and interview procedures between the two interviewees and the interviewer indicated by “.1 99 Episode 1. E-pair in comparing odds with evens and odds with integers Speaker What was said What was done 38. I [show the card “A: Odd numbers B: Even numbers”| What about, Show the card you know, odd number and even number? 39. E4c We do technically...1’d believe it’d be even because the numbers go on for, you know, infinity, and there are...they’re infinite numbers...so every time you go up one, go down one, etcetera. It’s either an odd 80 number or even number and it’s never ending. So, I’d say that it would be even because we know that there won’t be one more odd number than one more even number. 40. E4d Yeah, that’s pretty much it, that’s what I put too, I think. 41. I You first responded, you know... 42. E4d [take a look at his questionnaire] Oh, I put even numbers I think. Yeah. 43. DJ Right 44. E4d I don’t know what 1 think...I was just trying to figure out the answer so I put even numbers because, uh, this doesn’t even make sense now that I look at it again. So, it was just, kind of, putting something down, but, I mean, I couldn’t think of a way that you could have more even numbers or more odd numbers. So, I think there’s the same too, 1 just thought we had to check a box, so I checked at box. 45. I But then first, you know, when you checked even numbers, did you think of anything? 46. E4d Uh, just kind of, um, zero is an even number 47. l Uh-huh 48. E4d And so, you start with zero, and then, for some reason 1 was thinking, the numbers, itjust seems like zero is before all the numbers and so there would be more even numbers, but that’s not right...1 don’t think. 49. I [show the card “A: Odd numbers B: Integers”| What about odd number and integers? 50. E40 Uh, I said integers because an odd number can be an integer. So there are, uh, and then even numbers are also integers 51. E4d - Yes 52. E4c So for every odd number you have, you get an integer anyway, so even though that they go on, for, um, you know, there...there are infinite numbers, or infinite integers, it’s still odd numbers are integers. So if there was a breaking point, there’d be more integers. 53. E4d Yeah, it’s. ..1 have integers too just because every whole number is an integer, and any, I think, isn’t it? OK. And, uh, I just thought I’d make sure before I said that, um, and, 1 mean, that’s twice as many as there are odd numbers if you have the odd and even. Episode 2. K-pair in comparing odds with evens and odds with integers 45. I Now then [show the card “A: Odd numbers B: Even numbers”| of which are there more? Please check one of the boxes. How do you know? 46. K6b I didn’t check this one either 47‘ I Um. .. 48. K6b Because odd numbers and even numbers are not finite 49. K6a I checked on even numbers. 50' l Um... 51. K6a Just 0 is...in my feeling, 0 seems to be included in even numbers. So, I feel such a feeling though, but it seems not to be. 52. K6b So, looking back, it seems not to be... 53. 1 Please talk with each other about the problem because you have different thoughts. 54. K6b Key point is whether or not 0 is an even number. 55. K6a But, if it is seen from a certain point, we seem not to be able to decide that 0 is only either an even or an odd number. In my feeling, 0 looks like so... 56. K6b But, when they are expressed with n, even numbers are expressed as 2n and odd numbers as 2n-1 like these....but if we substitute 0 for 81 Show the card Show the card n...then....Uh! It seems to be right. [...] But, my thought is ....and....afier listening to that, it seems to be right....what I thought...so, we can count finite numbers, can’t we? Because I thought that we cannot count infinite things, I answered so. 57. I So, because they both are infinite... 58. K6b Yes, they are infinite. 59' I Um. .. 60. K6b As a result, because there is no end in a single word...1 thought that we cannot say that one is more than the other. 61' I Um...then [show the card “A: Odd numbers B: Integers”] What do Show the card you think about the next problem? About odd numbers and integers 62. K6b Oh, integers 63. K6a Me too. Integers 64. I The reason is? 65. K6a I thought that integers are....integers are divided into odd and even numbers. So, because integers are a bigger range. ..I thought that the cardinal number of integers is more. 66. K6b Because I thought that the set of odd numbers is included in integers. 67. I Do you have anything else to add? 68. K6b No Item 111 Item 111 in the questionnaire was very similar to the third question in item II except for three differences. First, in item 111, odd numbers were replaced with even numbers to be compared with integers. Second, the sets A (integers) and B (even numbers) in item III were not described in words, but represented horizontally and in parallel by using the set builder notation. Finally, the wording of the question in item 111 was different from that in item 11. In item III, the question, “Which of the two sets A and B is bigger?” was used, whereas the question, “Of which are there more?” was asked in item 11. The intention of item III was to check the impact of these technical differences, especially of the different wording by the use of the adjective “bigger,” which implicates reification of the infinite set, instead of the adverb “more” that is less dependent on reification. 82 Sr. ' ”7,; Us \ E‘lmf K-lnle \ 5pm Table 4.29 Distribution of endorsed narratives in item II-c and item III . Endorsed narratives Chi-s uare Compansons Students A = B A > B A < B Can’t df Valucb Sig._ E-interviewees 15 % 30 % 55 % 0 % III. Integers (A) and K-interviewees 15 % 60 % O °/o 25 % evens (B) E-participants 23.5 % 19.7 % 47.7 % 4.5 % 3 93 68 000, K-participants 18.3 % 56.3 % 0.8 % 19.8 % ' ° E-interviewees 10 % 10 % 80 % 0 % II-c. Odds (A) and K-interviewees 5 % 5 % 70 % 20 % integers (B) E-participants 15.2 % 8.3 % 61.4 % 3.3 % 3 15 61 001, K-participants 6.4 % 1.6 % 73.0 % 10.3 % Note. ‘Differences are significant (p S .01). Missing data in item 111 were not included in the table (4.5 % of the E-participants and 4.8 % of the K-participants). L. The changes in the question III in comparison to [Le did have an impact on the responses of E-participants but not on those of K—participants. K-participants’ responses to item 111 showed similar distribution of the four endorsed narratives (Notice integers (B) in item II-c and integers (A) in item III; 73 % and 56.3% in items II-c and 111 respectively). In other words, a dominant endorsed narrative in the K-group was that integers were bigger (or more) than evens (or odds). However, a major endorsement in the E-group had been changed from item II-c to III (Integers; 61.4% in item II-c versus evens; 47.7% in item III). Many E-participants changed their endorsed narratives between items II-c and III because of different prompts (more in item II-c and bigger in item III). Table 4.30 Distribution of the word use of bigger . Chi-square Students More numbers I-I1gher values d f Value Sig._ E-interviewees 45 % 50 % K-interviewees 100 % 0 % E-participants 38.6 % 46.2 % 2 82.12 .000" K-pgrticipants 86.5 % 0 % x"Differences are significant (p S .01). M. The change in wording influenced strongly the way E-participants implemented the comparison of sets, but it did not change K-participants’ choices. The word 83 L". .. 4 .)r-z- h "Hr- i.‘ is: bigger seemed to guide the E-speakers to two different understandings: more numbers and higher values. About 50% of the E-participants indicated that the meaning they ascribed to bigger meant increasing faster. Some of the E-interviewees explicitly hesitated between the two possible interpretations of bigger in this context. In contrast, all of the K-interviewees accepted this question as being the same as the previous one in item II (“Of which are there more?”). Table 4.31 Distribution of routines in comparison tasks in items II-c and III E-speakers K-speakers Routine Interview Survey interview survey II-c III Il-c III II-c III II—c III 1) Comparing by counting 0 % 10 % 2.3 % 0.8 % 0 % 0 % 2.4 % 10.3 % 2) Comparing that involves treating size of infinite sets as subject to the same rules as 15 % 0 % 7.6 % 1.5 % 0 % 5 % 0.8 % 2.4 % that of finite sets 3) Comparing the number of elements in two sets without specifying how the 0 % 0 % 0 % 0 % 0 % 0 % 0 % 0 % numbers were found 4) Comparing the size of corresponding elements of the two sets 5) Comparing the size of corresponding 0 % 5 % 0 % 2.3 % 0 % 0 % 0 % 0 % partial sums of two sets 6) Checking two sets for inclusion of one of . 75 % them m the other 7) Comparing the numerical range covered by the elements of the sets 8) Constructing one-to-one mapping between the sets 9) The use of the assumption that any two infinite sets are equal 10) The use of the assumption that infinite sets are incomparable 0% 50% 0% 43.2% 0% 0% 0% 0.8% 20% 50.0% 15.9% 80% 55% 67.5% 42.1% 0% 0% 0% 2.3% 0% 0% 0% 0% 0% 0% 0% 0.8% 0% 10% 4.0% 12.7% 10% 15% 16.7% 23.5% 5% 5% 2.4% 3.2% 0% 0% 2.3% 3.8% 15% 25% 10.3% 21.4% I I) Non-numerical comparisons 0 % 0 % 0 % 0 % 0 % 0 % 0.8 % 0 % 12) Unidentified routine 0 % 0 % 9.9 % 1.5 % 0 % 0 % 3.2 % 2.4 % 13) No answer 0% 0% 11.4% 4.6% 0% 0% 8.7% 4.8% N. A dominant routine in the E-group was changed from routine 6 in item II-c to routine 4 in item 111 but not in the K-group. In both items II-c and III, a dominant comparison routine in the K-group was routine 6 (67% and 42% respectively). In contrast, 43 % of the E-participants used routine 4 in item III, compared to routine 6 (50%) in item 84 Epit: Spea' llf‘ It ‘1'. 515 59 1 116.1; II-c. In other words, they employed the routines of “which one gets to infinity faster?” with the conception of increasing faster in the use of the word bigger. The following Episodes 3 and 4 exemplify the differences in word use and routine between the E-group and K—group. Episode 3. E-pair in comparing integers (A) with evens (B) Speaker 50. l 51.E7a 52. E7b 53. E71! 54. E7b 55. E73 56. E7b 57. I 58. E7a 59. I 60. E7b What was said What was done [show the card about item 111] What about this problem...which of Show the card the two sets A and B is bigger? How do you know? Um I said A since um even though the uh set continues um it includes more integers within uh... a set amount of uh like say if it was like 1 to 100 um.. A would include more integers than B would. Um this reminded me of the set before it except that I took the opposing stance this time. I said because B is increasing at a greater rate than A um... it would just be increasing to infinity just at a faster rate so that’s why I decided that B uh I thought was larger. ..Mm. . .It depends ‘cause bigger is such a vague term...like you can... Yeah it’s. . .1 didn’t really know whether to say like contains more values or has a greater amount inside of it or... Mm-hmm. Because they’re the same number of values in each set. . . it’s just the range on. . .on B is greater except A contains more. . .I guess. . .precise values or... Yeah Or uh smaller interval between values so. ..I guess that just depends on your uh idea of bigger and I just went in terms of its rate of increase. So do you want uh say something more- Um... About the other’s opinion? lt’s...it’s really hard to determine like you know differ between opinions since everything is-in infinity its all subjective to what your views on infinity are...it’s like um...l mean...l...l mean I can see from his standpoint how-where he comes from his conclusions so it. ..it’s logical. Episode 4. K-pair in comparing integers (A) with evens (B) 111.1 112.1(3b 113. K3a 114.1 115.1(3b 116. K3a Then [show the card about item III| Show the card I said it was A. Me too. Why did you say it was A? When explaining, I interpreted it this way. Of course there are preconditions and even though you don’t know what happens later, if [numbers are] listed according to this rule, A will be a set of natural numbers. The set B will be a multiple of 2, which is also a set of even numbers. Similar to the reasoning above, natural numbers can be divided into even and odd numbers, so B is included in A. Because of this reasoning, I thought A was bigger. Because they are sets whose cardinal numbers cannot be counted, I thought we could show what is big and small by the method of taking away if you can’t count them. If you are figuring out who is tall and who is small, you can find out who is tall by a difference when they are 85 standing. Just like this, you can see who is tall without measuring. Based on this concept, you can take away B from A and you will still have something left, sol answered that A was 100% bigger. 117. I Do you have any other thoughts about this question? 1 l8. K3a No 86 8:22: 2 m .< :::? 8:83 < 32 .:EM 8:558 ::68 o: o>3 38 8:83.252: 05832202 83 mom -.Iolofimuugmmoton. ofiflofiog a m: 22: 5: liilgaaamfiaaaflmgflflagiam .E2: 28:80 9 23:80: .0: 8.: 25¢: 05 3.: 8:88: 32 25. 83. A: m ::: 2&3: =u 2 <...2om2:_ z: mEom F: 8:83 < a 2 3m .8 3 3 2:95 m. .. =: 2 20E 5820:: .5032: 8:052: 2: ma. 2:8 2: 3 3 .8508 22:. . .< Fm: 2.5. mm 435.5: 8 cm .:3 3.: 8:83...:_mm: TEE 2:52 8 2 com 25: l----.110»...me58.5.8aflflmfiflamflwmaflmm: 8: :N m: T: :2: ::: : 8 HS 30 5>2£ :o m:5:::8 £3 :5 3 8:358th 30.9-05 : 2 22: 8:83...oE:.m Gm: 352 2.35:..a. .:o 22 2.: 8:5 a: 3:88.65 8.: 8:83 :ommE 83 m G: pom 25:: 2: =a .92: 8:83 :58 2: 8.: m: 30 :::. F2 «Ev. :ommE m: 92:520.: :0 m:_::::8 :3 2.3.: 8:83 :0::02 W: 8m 58 .::0 P22: .23 5m 235:: :o>8.:w 8 at! N :5: .30 52.: 52> 3%.: 23E:: 205 3 P22: 8:83...< 7.: Em T883 v 2.5 N 8233 8:3 m _81:.mmmm nWWmEMfldAmmaa «5. 23:5: Ems ::: 8238 3 P22: .2 9 50.5 8:038 22: .: Hm: ohm . 2:: 8:8 0.6. 525:8 2m 23E:: ::2 o:m:> : m. 5mm§3< :2: 22 552m a a mEmn2oE 2 m MN: 2: 35520 2: 23:0: 8:72:58 :0» .: 058 2: 2m :3... RS :3. . . . . . 35m -..---llflmo oummmwmmwmmw 552m a :o 8:12; 2oE....$o:1x .38: #5:: H 32 .m :2: flame“: 20E 8:22: «5.53:5 :8 «38:559. :8 2:. r : mum 2:885 m: 235:: 5.528 mEEQEoo .33 0E8 2: :_ $2 m 853: < 8:83 :ommE 83 < E 2 :35 2: :2: 205 m: :22: 23E:: :32: :08: ::: :::22: 5822: m: m 85m 8: 28 Ho: 5 5:33 2:8: 858 2: 25:: 2: >2: 8:88: 82 :3: com umme 2m 53 3:1“. :wmmwwfiwmmmmiawlwmmAmEfi....ammflm. :m:o_: :o>o...2oE : < mo :3E:: 5:28 2: 8:83 < mom: 3v— bu>o 95 3.8:: ::: oE: bo>o 0:0 .3 8885:: :::...m :2 3m $3— 3 :2 :::o: ::m 05-8-30 :38 8203 35.5: 2: E2: . . mo :3 8:83 232258: ...m :8 8535 < :8 8:85 : SN: 32 a 3 P: d: E2: :38 :93: .88 E Ems. 2: 235:: 82: 85m mm :mm 535:: 5:28 85:25:: 2: 53 8:83 oEEmmEOuE mm. 8v— Eow2:_ and: wEow “5.71: : 8:83 23E:: 2oE o>3 2:95 < a- 08 m§| 8.: 8 23:5: 22: 8.: :ommB 05.3: :0» So: :0 3:33 : :2: 33: 2:3: 3 E: m .< .:o 0::; .3: :om...< mo 83:. was}: 2 m 8:8 m E 3mm :ommE 83 < .< :_ 8.5.0:: : m .23E:: :0>0 .:o :8 m .N .:o 22::E «....m 235:: 555: .:o :8 m...< GS 8mm? 82: 83 < :mfimflmwwxmlflmwdwfl. 23E:: >=~1=1_-.m.m.:lum1o1>.mmflmm mEEoEOm 3:: ::m E? :o» ::: < Ea: m .33: 8:3 :8 :o> EN: «MM 2:03 m ::: 35%: 2 :3E:: 2mEm .Co>o 8330:: : 8:83. . .< 5 «B N 3 8885:: m :::. 8:8 25:: E: M: :2: :u>o ...o 5 m 3 9 £0 8.: . : =a E2: _ .3 888.5: 7: 8:83 .om .m :2: 332m 205 5c moom < em as. 28 :0» .: 8 ::: .235: :ommB 58E .3: Ems: _ 8:83 m v ::m m 8 8:8 8: o: < E 82: 53 .< 8 2: m E 235:2 mm «Q :o mEmw Q8: 3.: 8:83 :58 2: 35. M 3m m me 535:: 12:28 2: m: < :o :3E:: 5:28 2: .:o ::: mm :3— oEmm 2: 3 2:03 2: . :::: 8 :6 2.8.3— N 5m -Ijmaqmwflaammmmwwflgéaflaa:f< 5 EV— llammmlmmvwmfllommfiomimq n.olE.Mm-Hm-mm-vnm§mwzlmm&1&N: 222 ._ gm A... .0. .3 .N_ .o_ .w .0 .v .3 .1. m ::: A... .w .N. .o .m .v .m .N .3 u < @505— :o» 0: Bo: wuommE : m :::. < 38 0.5 2:.3 :2; .:— E :5: E 20mg: ::: 23:5: :0>0 8253 38:22:55 Nmé 233. 87 Table 4.33 Distribution of processual and structural uses of infinity . Chi-square Compansons Students Processual use Structural use df Value Sig.__ E-interviewees 90 % 10 % K-interviewees 25 % 75 % III. Integers and evens E art' . ts 46 2 o/ 6 l o/ -p lcnpan . o . o 2 53.32 .000“ K-participants 13.5 % 38.1 % Note. l'Differences are significant (p S .01). O. The phenomenon first observed in [G] returned. Many E-speakers spoke about ,9 ‘6 infinite sets in terms of processes (“goes to infinity , goes on and on”, “continues forever”, “keeps going on” etc.). Such reference was rare among K-speakers. Once again, the Korean responses were formulated in a more formal mathematical way (e. g., “there is one-to-one correspondence” (see [28] and [36])). K-speakers also explicitly referred to cardinality of sets ([22], [27], [29], and [34]). Such reference did not appear in the E- speakers’ responses. According to chi-square statistics in Table 4.33, this difference between the E-group and K-group was also significant in the survey participants’ written responses. Item IV In item IV, the relation between two infinite sets was unspecified. The wording in item IV was different from those in items 11 and III. The word larger in item IV was used to compare two infinite sets rather than more in item 11 or bigger in item III. 88 Table 4.34 Distribution of routines in cormarison tasks in items III and IV E-speakers K-speakers Routine interview Survey Interview survey III IV III IV III IV 111 IV Rejected the possibility of inequality of infinite sets (claimed infinite sets must be 15 % 20 % 27.3 % 15.2 % 30 % 5 % 24.6 % 7.9 % equal or incomparable) 1) Comparing by counting 10 % 0 % 0.8 % 3.0 % 0 % 5 % 10.3 % 3.2 % 2) Comparing that involves treating size of infinite sets as subject to the same rules as 0 % 0 % l.5 % 0.8 % 5 % 0 % 2.4 % 0 % that of finite sets 3) Comparing the number of elements in two sets without specifying how the 0 % 15 % 0 % 13.6 % 0 % 0 % 0 % 1.6 % numbers were found 4) Comparing the size of corresponding 50% 25% 43.2% 17.4% 0% 0% 0.8%16.7% elements of the two sets 5) Comparing the size of corresponding partial sums of two sets 6) “id” “”0 se’sfo’ mam” ofa“ of 20 % IS % 15.9 % 16.7 % 55 % 75 % 42.1 % 48.4 % them m the other 7) Comparing the numerical range covered by the elements of the sets 3) comma” one'm'o’w mapping 0 % o % 0.8 % 0.8 % 10 % 5 % 12.7 % 3.2 % etween the sets 9) The use of the assumption that any two infinite sets are equal 5% 0% 2.3% 2.3% 0% 0% 0% 0% 0% 25% 2.3% 5.3% 0% 5% 0% 4.8% 15%20% 23.5% 5.3% 5% 0% 3.2% 0% 10) The use ofthe assumption that infinite 0 % 0 % 3.8 % 1.5 % 25 % 5 % 21.4 % 4.8 % sets are incomparable l I) Non-numerical comparisons 0 % 0 % 0 % 0 % 0 % 0 % 0 % 0 % 12) Unidentified routine 0 % 0 % 1.5 % l5.9 % 0 % 0 % 2.4 % 8.8 % 13) No answer or I don ’t know 0 % 0 % 4.6 % 117.4 % 0 % 0 % 4.8 % 8.7 % P. The K-speakers were more open toward the possibility that two infinite sets in item IV can be unequal. Of the K-participants, 82.5 % reported that they accepted the endorsement that the two sets A and B were infinite, but A was larger than B, and 67.4 % of the E-participants reported the same thing. Many E-speakers (23.5%) and K-speakers (21 .4%) who used routines 9 and 10 in item 111 changed their routines in item IV because they accepted the claim that the infinite set of A was larger than the infinite set of B (see 5.3 % of the E-speakers in routine 9 and 4.8 % of the K-speakers in routine 10). With the prompt larger in item IV to compare two infinite sets, only 17.4 % of the E-speakers used routine 4, compared to 43.2 % of the E-speakers in item 111. Interestingly, the use of routine 4 in the K-group increased from 0.8% in item III to 16.7 % in item IV. 89 Table 4.35 Distribution of the word use of larger in item IV . Chi-square Students More numbers Higher values d f Value Sig.— E-interviewees 75 % 25 % K-interviewees 100 % 0 % E-participants 42.4 % 22.7 % . . 7" K-participants 65.9 % 13.5 % 2 9 96 00 ‘Differences are significant (p S .01). Q. Some respondents compared the sets with respect to the size of corresponding elements rather than with respect to the amount of elements. The majority of E- speakers (42.4%) and K-speakers (65.9%) reported that the word larger meant that there were more numbers in A than B. However, about 23 % of the E-speakers considered the meaning of larger as either increasing faster or larger sum in item IV, compared to 13.5 % of the K-speakers. Many participants often used the example in item III to explain that A was larger than B. The chi-square analysis of the comparison of the E-participants’ and K-participants’ responses about the word use of larger indicates a significant difference, as shown in Table 4.35. 90 m :05 590. m. < 50.8308 053 05 E m 8.5.0:. < :02? En. .25. < :. 50:23:00 2 m 83 20m. 0.23% m. conga m A w w 020. 05 0.25 . 00:00:80,250 0:99-08 0: 2 0:05 .. Fm. 2.5. m5 022 :0>0 05 .:0 m. m 0:0 8:. :0 0.2 00:80: :0 5. m. < ”a: 00m. 02:22 05 50: >05 3:05 :0>0 500:5: :0>0 :Ev. 2&5. . . .203 .::0 053m :05 BE :wwwwmmmwmmmmflmmmmmwwmfiw 50m. . o m. m 25 2085:. m. < :05 52:80 03.2 m :05 59:. m. < Gm. 0E2 30.. on 0:0...b.:¢2 28.00 3.5.22 05805.52... 2 2.028 02... 3... 00m. 82m 05 E00 :8 :0 0.25 2:05 .... 3 am 50305 02:0 £58 2 2 508. m:2:.5| :0 ..0E0. 920: :0.“ 50.08 :0: 80: 0:05 025.22 05 50: 205.: Wm. 55. 8.3 .....055: Ema. a :0 $53. :0 50.0508 .090. 0. 3.. < 3: 20m www.mxomflwmm.wwxwmmmmwtwwwmmmfifimwm. ..Mm..“ :0. 0.88 ::ouuwwmmmmm. 02... 2280520: 025.00. :0 .0 8.8: :. um..“. m20m $2 «Ev. 02.: 5:50:00 a am 50085:. 205350580: 50.55 05 .20 05:0: :. W: 8m. 0 :8 500: 50 50:5: .8550 50:0 8:...5800 0:88 L0 5.. . < :_ E0055 0:9: 0.0.05 05800 .090. 0.2 T»: 552:: .8550 05 82:80: .0252. m. m 25 <20 20%.. 2mm. 05. gm $880.0 .0 200:5: .8550 0:05.020. .0 2.0080 0...... “mm. $25 088 05 00:83.5 :0 0::.E00 2:03 200:5: ::m . 03. .055 on 2:03 < :05 .2055: .20 How :08 :0 25.. a 50 :0» 0. Hm 1 0R. 550 00v. 2055: .8: :0 E 828:8 5: 50m 025.5. :0 m. 0.055: 200 3: sum 05 :_ 00020:. 2 E05 ..0 0:0...38 020:2 500 05 m 25 < S m. 03. 2 .20 028. 3085:. 0.0.: 28:00 22 025:. m2 5:05 :0>m. E 2 05m. .025 E 05 0 50580 :::00 8:80 8m 0 0 :0. _ 80:0 0: . .2 . 0>_w.:.0:. 50:00 .003 0:0 0.25% 03:25.“. 0: «...—“.08 10.2 Dev. 58:. 0n. 2:03 < 0m m :05 300:5: 0:08 032. 2:03 < 8.. new 8.5.0:. 0.2 $25 000E 8220:. 8.20:8 02h 3m. :3. 0:0 3 8.0852 P2 0580: :8 mm...“ c. 50520:. $055: .80H :0. 00m. 222:: .055: 25.3 00020:. 05. 2055: :0>0 00:83. EN. :3. m :00 E :05 < :0: 2 20.85. 0:05.525. 9 mEow 2.8» 2. E 0mm. ...85202 2 00:83:02.”,20 0.50:5: 05:: m0: 2 0m 25 3:050:05 5:25 3 a: flow 2 F. 2.00:8 05 .3 0305058 05 m0~.m 05 50 .0252. 05 50m Fm. umv. . . 0mm. guwa. m. 820555: :0>0 m. m 25 3005:: .055: m. < Gm. 5203 55.0 50 . . . 03. 020> :03... 0: 2:03 50 85: 55 0:0 05 00... m. 2&5. 0v... .00.: . 3. 0mm. Swmm. m. < 5.3 m. :mflflmwwflmmflmmm mmmwwmmwwmédwwmufimadmmxmfi. 0: 920w 2 0:05 .< E05 m. 50 00.8 :0»... 52 022.22 05 50m RN. «3. :00 05 25.3 2005:: 20.: 82 2 .2 m. 592 ..8 2:03 . .33 02... mm. 0mm 2.: 50505 00......m mo $850.0 8: < 7%. £2 20.: .3 88:02 :8 2 00... Emmi. 8w 2:00 2 :2 3m .5 62:2: 9.... 822.. a; ...W 3:83 a9: m. < .8. «N0. 0.50:. s new :_ 2 .06» :5 2.22.9 .m. 2.0 £0025: :0>0 :05 :0 5. 05 0:0 8:. 0:8 05 00 2:03 0:... 0:00:28 20 250:5 02.52 :0 90:05 :5 .02—Ea. 500 05 m 0::. 8.48.005 0:255 05 30.... Km. fv. 4:050:05 :::—m a .3 m:_0w 0.2 .2 :0>0 3:8. 53:. 09 2:8 >02... mm. gm. 0 :«mflwwmwwdlmmamwfi lll:i-l.m..mw::_u:.mm.-mm_wmw@fic mmmmazamwzamfizflmfixmmw 8.9.015- 050:5: :0>0 0.3 0:05 5:: 2055: .055: :0 m. < 0583. EN. 03. 0. a: flow 2 :023...:0=22:E 5:95 a 032. 2:8 2 :05 Swan. 0. < 2. gm 5:02: 0.5 :8 5055 .m :05 59:. m. < 50 625.2. m. m 0:: < 300 03: 02:0 208 :05 £220 .828 < .>. >. 802 5 m 25 < $00 0::—ME 030 05 0003500 mcomtwaoo end 030p. 9| Tabla . 1 form ..i,\. on“, ~\Hiii Table 4.37 Distribution of processual and structural uses of infinity . Chi-square Compansons Students Processual use Structural use df Value Sig._ E-interviewees 75 % 25 % Even numbers and K-interviewees 20 % 80 % integers E-participants 35.6 % 2.3 % 2 69.50 .000“ Kjiarticipants 4.8 % 36.5 % Note. ‘Differences are significant (p S .01). R. The same as [G] and [0] above. K-speakers’ discourse on infinite sets was seemingly more structural than that of E-speakers, in spite of the fact that only the latter used the noun infinity. K-speakers’ talk was more formal mathematical. The majority of K-interviewees consistently focused on one-to-one correspondence as well as cardinality of sets. In contrast, the majority of E-interviewees employed infinity in conjunction with an infinite process to compare two infinite sets ([1-9], [12-13], [15-16], and [IS-19]). The chi-square results of the comparison of the E-participants’ and K-participants’ responses about the use of infinity show a significant difference in Table 4.37. Item VIII-a 92 0.0:... 9 0:00 ...... 00:.0> ..0 .0005: 02:22 :0 03... 0. ...0 0... . .052 ..000. ...00.3 0.080.. 0. 00:2.000 7:0 000 :0 000300.. 0000.020 0:... SE ..Ev. 0. 0:228 0.:03 0 000 000.0 .0>00 0000:000 0:20... 0: 0.0.0:... 8N. 00m 00.....00 on. .0008 0:0. .00. 0:... 00000000 02.0.2. 00 0. 2 an. 00.0. w0.0w 00000. ... . 2:... 0: 0. 0.02... 3: 00... 0.00. 000 0.0.0 0305:5002000 30.» 0. 0. 0000.0 0...... .mm. 00.0. 00.50.. 505.3 w20w 00000. 2 S .. 00m. .2002 20...... 0. 000m 0.03 05 00 .05 00... 3.5.2. 0. 000m 000 0.0.0 000 0.0... 030.» _ 00:80 .50 00 0 .00 0.0.0300 000:0 >00 0 . :03 0.0 H . 0.00200...b.2.2. 0. .88 :0 M.20... $25.2. 0. 000m .. 0< Km. 0.0V. .. 0 0 ... .2 . .0. . 2 n . 2... 2 00m. 0000.000 ..0 0000.02 0. 0000 ..0>00 00:0:000 02... G : 0:228 ...»..22. .:0 00.000 3.2.2. 0. 000m 0 00 0. =0 02...... En. 55. com 22.50. 0. 000m 2 0000:000 M20850. :0 b.0000.» 0. :0 Rm. 000. 50.0.. :0 0:228 ...3 2 .2. 00m. 00000020....5 0.030. 000 0.0.0 .00 0000 0:.0> w22.2. 0:... Fm. 05. .02»... 000 5.2... .0m .02. x05. . .22.. 0: 0. 0.0.. .r .0: 0 0m. 83020 00000000 0:... TH. 00v. :0 000 :0 000m 2 . . 0.00.50 ..0 .5020 022.2. :0 0.0 0.0:... mm: 0 0m 0.0008 0 00... 025.0005: 0 .00 0.2220... .05 00... 89020 .202. 0. 000m :0 .mm. 03. 00 0.0.05. . 00:00 205.3 00.8020 03200.. 05 2 00000.00. 2 .N. 00m. Illilflfimm. 0. =04».I..1.m..........0.l000w 0 02:..I.I0I«wud~.wu...flm...10w 0.. .m00.awl00l0m0.mwumw. . 0.0.0. ..W 00:0..000 8000.000 05 00:80.. :0 2.20000 .00. 05 .0: 0. 0.02... E m. 00v. .5200 02:..2. .0 000038 05 ..0 000 05 00 >222. 0. 0» .50.: E : 00m. 3.5.2. 0:22 .0 222.2. 0:... .0220 0. 00w.0>.0 2 mom. :3. 20¢... 0. .:0 000w...0:0:2.000. . .000 ..00000 .. 8: 0.0m. 0.0:. 000 0.0.: 220.02 0. 000w 2000300. 0.... .0 00.0 0:... mom. 00v. 2:... 00 00.. 2 ..0wmfinmm0dmiwwMEHmWwdolwmwmflwmlmfl. 00m 20...... 0. 0w. . 020.. 000.... 0 ..000. .0: 0000 U6 ..0 0:.0> 0...... EN. :3. .03... 2.000. 00000. .05 00:0:000 < a: 0mm. 0.50.... . 0. 000w 0:0 0:.0> w2w.0>000 0 505.3 0000.00. 0. 00:05:00 2 Fm. 03. .0520 .0 0wa 0.0w 2 05023 :0 w20w 00000. 2 F. 0mm. 022.2. 0.00 0.. :00 00:0: 00 0.5 ....... 500000.02 2000.000 .0 2000.00. 0... .0 00x... 0. 1:0 000 :0 0003.00 00005.20 02... SN. :0. 0.22.2. 0. m20w .0 2.0.. 0 M23... 00... 02028.0 3.03:2 0.0m 2 G. nwm 0000.000 .0 0000.00. 0. 0:228:00 00 :0 ...0 000.0 0:... Wm. 03. w0.000.02 00000. < .0 0:.0> 0.. ... .50.. 0.. 3.00. .0008 2 .3 0mm lama. 0. 0:.0> 02 0008.02 72.0020. 0.02.0 .0005: 05 0003 H08 09. 2.00.0.0 505.3 8000.000 052 0.025.. 020...... 0.0 0.0:... .0. 00m .00 020.2. 00 00.0000: ...0. .05 22.05 . .mm. 09. 92000.02 00000. .020 2 .2 00m .52. 0. 00000.02 2 .. 005 0.0... 0. . 002330000002 000 0.0005: .0000: ..0 0. .030 ~0 ..0 00233800800 0.00.000» 0.0 00001000 0... ... NS :5. .3 a: 000m . . .220» 00000. .03 2 00.0.2. 00... 0:0 0 00... 0. 000m .. .3 00m. 0.:.. 5%... 000 .03... @000» ..0 0000. ...3 .02. 2 2. 00m. 00.:w0. 0 5.3 2.000.000 000 20:82.08 92000.02 0000:. 2 H .N. 0.2 . . . . . 0000.: 0.5 0000 .023 .202. 0. 000m .00 00 ..0 0000:000 0 .05 0.20.0 .8050 < A3 :.> 0-..; .00.. 0. 00.0000... 05 0.. 000009000. ”an... 030... 93 Table 4.39 Use of infinity in a seggence Chi-square Students Processual use structural use d f Value Si . E-interviewees 95 % 5 % K-interviewees 25 % 75 % E-participants 65.2 % 6.1 % , K-participants 11.9 % 57.] % 2 1020 '000 ’Differences are significant (p S .01). Missing data were not included in the table. S. E-speakers’ responses were relatively consistent and in tune with the canonical interpretation of the word infinity. K-speakers’ interpretations were more diverse and often inconsistent with the canonical interpretations. Almost all E-speakers translated the expression sequence a 1, a2, goes to infinity into utterances saying that the sequence is in the process of unbounded or never-ending growth (see [1-3], [5], [8-9], [12], [14] and [18-20]). K-speakers’ responses were much less consistent. Many of them made no requirements with respect to the size of the elements of the sequence. This use was clearly phrase-driven (see [25-26], [30], [32-34], [36], and [39]). They also ofien made specific assumptions about the sequence (e. g., “a regular rule” [2]], “geometric sequence” [22], and “1, l, 1, 1” [26]). T. E-speakers provided processual explanations. K-speakers spoke almost exclusively in structural terms. Almost all E-speakers used processual expressions such 9, ‘6 as “increasing, getting bigger,” “keeps going on,” and “gets higher.” Many K-speakers did not mention any process, except simply repeating the phrase “goes to infinity,” used in the formulation of the question. Instead, they spoke in structural terms of “sets,” 9, 66 9, 6‘ “number of elements, sizes, values,” and “last term.” The chi-square results in Table 4.39 show a significant difference between the E-group and K-group. One word for a process that appeared in their talk and was not found in E-speakers’ responses was “diverge.” 94 U. E-speakers formulated interpretations in their own words. K-speakers used more formal mathematical formulations, even though some of them were not fully versed in it. Many K-speakers were careful to distinguish between the index of an sequence element and the element itself (e. g. [2]). Some K-speakers showed awkward uses of mathematical formulations (e.g., “A limit; n goes to infinity, an is infinity” [31]; see also [36-37]). They often provided formal language to define going to infinity such as “converge” and “limitE” (see [27], [31-33], and [36-37]). V. In particular, unlike in the previous items, K-speakers used the noun infinity, but they did it in phrase-driven way, by simply repeating the expression goes to infinity that appeared in the question. The phrase-driven rather than structural nature of their use was evident from the fact that the word infinity did not appear except in this phrase. The K-respondents clearly had difficulty providing an equivalent statement expressed in words that was different from the interpreted phrase itself. The following Episodes 5 and 6 exemplify the differences in defining that a sequence a1, a2, a3,. .. goes to infinity between the E-group and K-group. Episode 5. E-pair in defining that a sequence a], a2, a3,. .. goes to infinity (item VIII-a) Speaker What was said What was done 238. 1 0k. [show the card about item VIII-a] What about this problem? A show the card student claims that a sequence goes to infinity. What does this mean? 239. E6b Uh...l wasn’t sure if that one was a trick question because it’s pretty simple. I mean you just keep adding maybe it’s the uh what are these things called. Can’t remember the name of them but one of those sequences where numbers become. . .have the same equation and they become larger. What is the name of that? I can’t remember. But maybe its like one and then one plus three and then two I mean you know four plus three or something like that but. Regardless the sequence continues forever 240. E6a Keeps on going and going and going getting bigger and bigger the sequence does not stop. It has no limit. 241. I 0k. what do you mean by you know the sequence is continuous? 242. E6b It means it.. . it doesn’t end. There is no set ending or beginning its continuous it doesn’t stop. 95 243. l 244. E6a 245. I 246. E6a 247. I 248. E6a 249. I 250. E6a 251. I 252. E6a 253. 1 254. E6b 255. 1 256. E6b 257. I 258. E6b Do you want to add something else? Like 1 mean if you had a sequence when. ..where you’re adding numbers... Mm-hmm. like say this was one and that was one plus two and this was one plus three it just keeps on. . .keeps on adding more... Mm-hmm. and more and Mm-hmm. More and more actually so you keep on going to infinity so. Mm-hmm. Anything else? No. Do you want to add? It basically goes out to infinity. About uh go to infinity? Well that’s what I meant by continuous. It doesn’t have an ending Mm-hmm. You can’t say it stops at a certain point it goes to infinity. Episode 6. K-pair in defining that a sequence a], a2, a3,. .. goes to infinity (item VIII-a) 159.1 160. K2b 161.K2a 162.1 .163. K2a 164.1 165. K2b I66. I 167. K2b 168. I 169. K2b 170.1 l7l.K2b Now then [show the card about item VIII-a] A student claims that a Show the card sequence goes to infinity. What does this mean? [...] 1 don’t know well what kind of sequence this is...if list [sequence] by numbering like this, then here 1. ..when the number of here [subscript] increases. . . its value is infinity. [...] l also...same... When you answered last time, you seemed to write that it means {an} is an infinite sequence Then as soon as 1 saw it, I thought so. When this is represented by a set, I thought that it becomes an infinite set and I solved it. When I heard what he said, I thought this was not... Can you explain this more? So, a1 is a certain number and a2 is some number and like this way. So, because the sequence is not known, if thought in this way, then a really big number of a is substituted, when to be listed...really...if listed from left, if picked up a number way to the right, then there is a certain number. 1f 1 go to right infinitely, 1 pick up this. This can be expressed like this [write an]. Because this goes to infinity, this value also has infinity. Yeah. How far does it go to the right? It should go infinitely Here you wrote the symbol of ago. What is the meaning? Please explain it concretely In the case that this is not a finite sequence which has a limit (Jae-hon), but an infinite sequence, so. . .there is an increase or decrease or a regularity which a sequence has. That this [sequence] is infinite means that it cannot go due to endlessness. If 1 pick [it = ago] up here. ..if I can pick [it] up, then it says that this [sequence] will become like this. So, it’s approaching but reach. . .doesn’t seem to reach it. Even though it [ago] cannot be picked up, if [1] go and pick it up, it’s going to be infinity when seen within the rule in this. That kind of story... Anything else to add? A sequence is the array of numbers which have a rule. Then, 1 don’t 96 know how far a [term] should be. ...if the general term of this sequence is an, going to infinity means the term itself...the number of term [11] itself becomes the value of the sequence. So, if an is equal to n, then going to infinity means value also infinitely....in this way. Summary: Discourse on infinity Table 4.40 summarizes salient characteristics of the colloquial and mathematical discourses on infinity in the E-group and K-group. Table 4.40 Salient properties of E-speakers’ and K-speakers’ discourse on infinity Item: topic Aspect E-spea kers K-speakers Used both the adjective and the adverb. They used the adverb when they were asked to create a sentence with the noun infinity (either mathematical or colloquial). Their uses of infinitely and infinite was mainly in non-mathematical context (even more so than in the US group). A. Infinite and Used the adjective, but not the infinitely: type adverb. The use was mainly in of discourse non-mathematical discourse - _ ' 'v . . The use was m the context of K speakers used the adjecti e infinite Item I: . as descri tors of concrete thin Creating [.3 1",]; mte and large “fem. E-speakers used the known ft: their large dimensiogrsis or of sentences infinitely: i‘dJCCtive '"fi""e.ah208t always , spiritual matters. They used the adverb with given context of use in fiOIljllflCthfl:Vlth number of infinitely as a descriptor of many, in words or amount Of' the context of sets. With just one exception, K-speakers E-speakers’ P53 ofthe word . did not use the noun infinity, either in ’"fim’y was massocration With its colloquial or mathematical version. processes,.which were S'fud [0 be When asked to construct a sentence C. Infinity never ending. The infinity itself with the infinityKCon, they converted was said to be unreachable or . . . . . impassable. There was no the noun into adjective (infinite) and . . . . . when asked to construct a sentence assocration of infinity wrth , , . largeness. With the infinityMcOu, they converted the noun into adverb (infinitely). Almost all E-speakers compared The 40% of K-speakers who chose an the two sets according to the option other than A=B did so because item I" . D 11 . number of elements, and if they their comparison was non-numerical. Comparing A.- f -a. _ did not choose the option A=B, pairs of two _ mgers, it was only because of the fact “‘3 B=toes that they interpreted the word finger as not referring to the thumb. u Only two fifths of E-speakers Only half as many K-speakers chose E. ll-b: chose the canonical response the canonical option A=B. Other A=evens; A=B; other responses were responses were distributed evenly B=odds distributed evenly between AB, and “can’t say”. and A>B. Only as few as 10%-15% of E- The percentage of K-speakers who speakers chose the canonical chose the canonical response A=B was F. ll-c: A=odds, response A=B; An even smaller than that of E-speakers B=integers overwhelming majority (80%...l!!._. (5% in the interview and 6.4% in the 97 the interview and 61.4% in the survey) chose the option A’ Iii-.‘fi m R....P!~d uldol)‘.’.FhAVf‘.PI.l.Jnh ))I|Ut~\’rhl NA.‘ ‘AV >I§~V-§--U i 1 1 I u u . I," N I .J‘N\~Niii m t. at .. , .5 $82.8 8.3:... mE-=o:H=oZux8:oo 8..an «En a .20 . . .... . . ... 5 S. 2 2.0 9.9.... .3. :95 “8588 ..Ev. .82 93.5.. m. .50.. ..o 2525 BEE .3. .82 a m. 8:5m53...o TEE...» L 33:... :02 new? :8 a ... @235 m5. 2.3 5.95.. < H2; .85? cos—.... 96m Hon 0:6. :02 :8. >... ..an 26.. o. 3...»... 8.=o> Ho: com :02 60.89... Hesse...» L :02 02.58. ..Ev. ,. ..oZ tugs... 9.0:. m£oom up... 3... >2 Hmil. ..om 3...... o... 28.0.3281... .3. .23.... 8.2.: 8.. $3 .on. 25. 5...... 3...... 8.: ... 8.6.5.. 2E ...: 8m. :02 En... T5233 :02 cogs... m. 855:0 Ea ..xo DEV. 111E:iil 3...? gmwwmw. «Wm ..om. L FEE: 2.59.30 :2: 2.... Hofl ...o...3 :. no.8 u... m. Bo... HwNL «Ev. :02 55...... NS. ow «.50 22.. 3.9.1.. S... «cm ......o..~.Eo..=. 93.8.. mo>.m 3&5 Hm z :02 22.. :02 v8.2... 83 coautoamcafi H. .L .52 8.2.3.. 1.!1 Wfilmaw 2%....mmfilcbrwafl .5. . . . , Em 7.5.56 L ..SE... o. 80. .. Hum. :02 3.3.5.... on :8 25.53:. :02 32...sz ohm. ... .52.... 3...... < .8. .5. .o .35.... 8%... a ...... 22: .2. co 2:238 8.3. 3:8 .52 u. 3.5: o... ...w.“ 2 we. 2.... ..oz 8...... 8...... a ... 2... 03 .2. ..8. ..oz 232.... .35.... ......E: a ......ofi .0. ..E ...:ow 2.. w:...o_..xu 2.52. 2.... H52 llfioflillmwfi? 62.—c: m. 22? 3m 03. imwfliivwmflczflalcwflmwwagaa Slow/.15... sum. 855E223 3.2.3.. cuss... Dev. .52 .63.... 2m 22... :30... N. pom. =02 H.652?» L 3:5: 0... oEOo..o>o :02 o. 2... .:o 28 22> .3... Emma... o. 9.9.: ......sz 9.2: o. .53 . Hon 8:82.. b... ..cu.:oo . HMNL 3v. 53>. m. 5.8:... £8.00 a ..o 52.5.. 0.; H3 3m. NocoE 2.5.. Hmswénm L no.5... nnv. .82 . . . :oZ USE... 5.3 ...... =8 03 .52 08% REE: m9. Sec. 5.5.. >2 H2 ..mm. o... .558. m9. .09... 5). meL as... 31.9.1.0 .onEzz 2F HNNL «3. 0mm. :0 Hagen...» L 3...... ”MAN...” ..o 2% ..o ...:o oh. 3?. 3 BE. m. .5525 u H L pmm. Z :2...» .0965. whonmwnwhfiar. HVML Z 3260... 8:8: oEom ES «3. .. .2 u . ._ . . . Fr v «mm. Jail .....2 ... 3...... 2...... ...... 2.. ...... .2. ..oz 3...... m. £95.: .8. ..S. .9. 2 ME... .5. 2&2. ....m. 11!...w17z. ...uflmwmamgmmfiflmczoco. =oZ bfiwmaol «NV. :82 ow :8 no» we. ...... ma m.......u8.E.... HQ $8338 L 93.5.. a 55.3 HNML 3582 USE... cm: 30:. Ho: uvm oocsmEzu...o owns. v2.8; a ...v. :02 m o. E ..o :2; 2.. .52 :52...» n. ......§..-.=§ SE: 5.2 . .3 .5 o... m. 9 o. .. a -1: .... 8...... a; 9...... .... .... Ewan... E ....m. a a... 58.35... 26... o: ..m. ...... .. .... . m .... .v. .52 mass... ...: N. 8.5.331: ....m. 3.850 8.5%.: 88:80 umcommom 382.8 |o§ Easiness... ..oUv.uo..E.... 3.8.5.... 28.3%2 28.3%-... v.53 532.0,. 0... 5.3 8:85... a 88.5 .x. Ea . 32.8.8. 3...... X. 98 . mEB. .... 38.5... 203 2.. mean... $209.2 30.38:. .0 bmfifism ...... 03.... O W .8800 30505050850: u .82 58.80 0.050.550... n 503. .082 0. 0 .... ..0 .000 was... 0 005:»... E 0 .....s. 0.”.Puuocch0 0.. ...... 2.02.2... ..0. ..oz ...... ...... 00...... .... w...“ .82 ...... ..0... 02. 80.2. .02... ...0. wow. 0.... ..0 00.5088 0M5. 00..E.. 05M 5...). 300.800. 0 ... 00 Co ..E: of ... . 0m .82 L ..E: 0... 0005.898 . HowL 50$. 0 55.3 .. 0>.000.. 0 .0. Hot 0:0. .82 ..E: 000 0 I . . . . . . . 0... 9.0.00... 8.. 80.0.. 0 .0» 000.... ...). Hmfl 00m .02 00:03.00 .82 .mom :8 5.5.5000... o. ..Ev. 502 N 0.0....0 3.05.0 ..E: 0..... Hen ..0m. .. w...30=0.. 05.8 ..E: 05 0...“. Hot :5: 0 0:80.08 .035 03 H03 0Ev. 53>. 2.0.0.60 0 00..000....n.0 .. 00 ..E: 0.. ... Hmfl 00m. .>.r ..083 :00 . 0:... ..oz .502... ..oz 0...... o. ...... .... 0. .. .00. ...0. ..oz .8... 32. :0 ...... a .82.. ...o... .2 .00. ...... ESE u. ...... ...... ...... .... s... a. .5 .82 .8500 0.808.. .0... :5... HS_ 05. .82 20?... ......E 30.. 0. ..E: 0 0.0.0:... H. 2 0005.80 b0> 003 . ...E: .0 800.80 .82 0 00:0..0 0 0.80... ....m. .002 . . 0......0Eo0 o. ...... < .00. 000. ......2 02.2.... 0.0 ...... 0... 0...... .00. 05 30.... 00E00. .0... . :05... HR. .82 ..E: 0 0000.. 0 3 H03 03. 00m. ..mw..0...0 .. 0 ..oz .82.... ... ...... 0... .8. _ ...0. ..8. ..oz ..8. ... ...... o. ... . .0... .00 .....o... ...02 .8: 532.... 0... ...... .0: 2:00:10... .....5 .....2 2...... x o. ...... a 0. 0.2.. .00. 80. .....2 0... 0. 8.6.5. .5028 ...o ...... 0... .0... .00 0.:0E.8..>..0 0.3. .82 0000.8 000.. . .80 :0» m......0.=0m Hi .82 H3858 L 330-25.-..03 02...... 0... .82 ..E: ...: 0005.898 . HNE 0. . . 0mm. ... 0>.>.=.0 0. 0...... 0.. 0. 000.. 03 Hwt mv. ..idvfllt1..=0..d,01..1&maiwwtm.l..w.i.flwmmm0 0:H.HWE. 03. 53>. 0...? ..E: 0... 0...... Hvt .82 00 :00 :3. 50.). ..E: 0.. 00.. .8500... 0:... Hm... ..mm. . . . ......a o. E... 0... 0. m.... ..0. ...... . . . ~00 000090380 .82 08.... 000.00... . 0. 3.5.00 ....0 ..0 ..E: 0...... How. 03. 0:0 0. 00.. .0... 0...”. ....s. 250.. ”...“...fi. ..an.=m.m..._.......m00_ ......w -15 .1208 ... 02...... ... ..2...0 03. ...... .. 0.2.3 o. .52. ......8 a 0.... .. ...E... ...... 5 . . .. 0 ... . :3 m0 2 00.05% 03... 0.000.. H02 00m. 00:03.00 ...v. .82 o :00 . ...,. 30.. .8 ..E: 0 0. 0.0.... m... ....m. .....2 2...... ...... 0... m. .. .35.... < .E .....2 02...... m. x... 00:... 2.. .00. 0.0. 0%.! 3. 8.... ...o 8...... ... ...... ....5 . wt... s... 08.80 00.8 00y. 08.80 008:0“... 08.80 00.8900”. 5020......5 .8855... 5.5.1. 0.8.0.0000. 0.003000%. 0.83 530.8,. 05 5.3 0008.80 0 0.00.0 .x. 0.8 . X. 0.8 . 080.. ... ...E... 083 0... m...0= 00002.00. 30.30.... ..0 585.56 NV... 0.90.... 101 EOE-I Table 4.43 Distribution of the contexts of use of the words limited and the chi-square results of the comparison of difference between the E-grorm and K-group Students Words Non-mathematical Mathematical None Chi-square . contexts contexts df Value S1g._ E-interviewees LimitedE 65 % 35 °/o K-interviewees LimitechOn 90 % 10 % E-panicipants LimitedE 50.0 % 34.1 °/o l5.9 % 8 75 003* K-participants LimitedKCo" 73.8 % 2| .4 % 4.8 % . . *Differences are significant (p S .01). A. Limited: context of use. Both groups used the word limited in any version mainly in non-mathematical context. Among K-speakers the phenomenon was stronger than among E-speakers. The E-interviewees used the word limited in both non-mathematical and mathematical contexts. However, the K-interviewees employed the word limitedKCo" predominantly in non-mathematical contexts (11 responses out of 14 for limitechO" in Table 4.41). The chi-square statistics in Table 4.43 indicate that the distribution of the word use of the E-participants and K-participants between non-mathematical and mathematical contexts is significantly different when the word limited is colloquial. Table 4.44 Distribution of the use of the word limiteda,” as an upper-bounded process Chi-square Students The use as upper-bounded process (if Value Sig.— E-interviewees (n = 20) 30 % _l(-interviewees (n = 20) O % E-participants (n = 132) 38.4 % kK-participants (n =126) 41.6 % l .50 .479 Bible 4.45 Distribution of the use of limitedKMmh as extreme . . Chi-square jtudents The use of limited/{Mat}, as extreme df Value Sig. E-interviewees (n = 20) O % iinterviewees (n = 20) 95 % E-participants (n = 132) O % . 2 . * j-participants gn =126) 42.1 % 1 63 6 000 I"Differences are significant (p S .01). 102 ill SOL .l :5: nor.- lie 1 the L spea 4.4—l ’her B. Limited: type of use. Both groups used IimitedCo” in the sense of finite (not infinite — something that has an upper bound) or restricted — one that could be larger. K-speakers used limitedKMau, in the sense of extreme. The majority of interviewees employed limited as something they could not go over in their daily experience (“height” [2], “as far as you can go” [3], “ability to learn” [8], “how much TV you can watch” [16], “food” [17], and money” [22] in Table 4.41). In the case of the Korean mathematical word limitedKMath, K-interviewees employed it in both non-mathematical and mathematical contexts. However, in non-mathematical contexts the word IimitedKMath was only applied to something extreme. This was not observed in the use of the Korean colloquial words (see [31-32], [34-41], [75], [78], and [80]). The E- speakers never used the words limited and limit in these ways. A chi-square test in Table 4.44 indicates that there is no significant difference between the E-group and K-group in the number of written survey responses in which the colloquial word limited is employed to refer to an upper-bounded process. All of the K-participants who employed the words limitedKMath in non-mathematical contexts used it as the concept of extreme, as shown in Table 4.45. Table 4.46 Distribution of the contexts of use of the word limit and the chi-square results of the comparison of difference between the E-group and K-group Students Words Non-mathematical Mathematical None Chi-square . _ contexts contexts df Value Sig. E-interviewees Limit}; 50 % 50 % ' ' 75 ‘V 25 °/ K-interviewees LfmftKColl o o __‘__ LimItho" 30 % 70 % E-participants Limit}; 28.8 % 63.6% 7.6 % l 76 l 7 000* K mid ants LimitKCon 81.7 % 12.7% 5.6 % ' ' P P LimitKCo“ 30.2 % 52.4% l7.5 °/o l .02 .896 *Difi‘erences are significant (p S .01). C. Limit: context of use. Both groups used the word, in whatever its version, in both mathematical and non-mathematical contexts. E-speakers used the word limited, mainly 103 in mathematical contexts, whereas K speakers employed it predominantly in non- mathematical contexts. The chi-square results in Table 4.46 show that the distribution of the word use of the E-participants and K-participants between mathematical and non- mathematical contexts is significantly different when the word limit is colloquial (x2 = 76.17, p = .000). However, there is no significant difference between the two groups when the word is mathematical (x2 = .02, p = .89). Table 4.47 Distribution of the use of the word limited; . . Chi-square Students The use of limit as an upper bound d f Value Si . E-interviewees (n = 20) 30 % K-interviewees (n = 20) 5 % E-participants (n = 132) 15.6 % l 6.00 .014 K-participants Q: =126) 15.4 % Table 4.48 Distribution of the use of and limitKMam as extremity . . . Chi-square Students The use of llmlt as extremity df Value Sig._ E-interviewees (n = 20) 0 % K-interviewees (n = 20) 30 % E-participants (n = 132) 0 % . K-participants (n =126) 30.2 % l 4625 '000 D. Limit: type of use. Both groups used limitcO” to denote an upper bound — something that does not let a thing or process to get larger (see Table 4.47). The usage of IimitKMmh as the concept of extremity in non-mathematical contexts was also seen in the K- participants’ written responses (see Table 4.48). However, the majority of K-speakers used limitKMmh mainly in expressions that were formulated as a textbook instruction to do something or as textbook definition. In general, it seemed that K-speakers were not very proficient in creating sentences with limitKMam. In several cases, the noun was converted into adjective. When it was used as a noun, the expression was personal (about a person rather than about mathematical objects) and appeared as if copied from a textbook (see 104 “find the limit” [74, 76, 79] for instruction; [73] and [78] for definition in Table 4.42). Finally, several pairs did not mange to produce more than one sentence. Item V In item V, the following table was shown to students along with the question “What do you think will happen later in the columns of this table?” Table 4.49 The table shown in item V in the questionnaire x J x + 25 -— 5 x 1.0 0.099020 0.5 0.099505 0.1 0.099900 0.05 0.099950 0.01 0.099990 0.005 0.099995 0.001 0.099999 Table 4.50 Distribution of endorsed narratives in item V Endorsed narratives fi-speakers K-speakers lntervuew survey lntervrew survey 1) The sequence is increasing/decreasing (without the limit) 30 % 29.5 % 0 % 2.4 % 2) The sequence is getting close to (or approaches) 0. l 30 % 29.5 % 30 % 27.8 % 3) The sequence approaches 0.] but never reach it 30 % 8.3 % 5 % 2.4 % 4) The sequence converges to or becomes 0.] 0 % 3.0 % 15 % 15.1 % 5) The limit of the sequence is 0.1 10 % 12.9 % 50 % 45.2 % 6) Other 0 % 10.6 % 0 % 4.0 % 7)No answer 0 % 6.1 % 0 % 3.2 % Even though some students made a mistake and answered one or 0.01 instead of 0.1 as the limit, their responses were categorized as one of the five endorsed narratives because they showed the same idea as one of them. The “other” category in Table 4.50 is the case, for example, when the student writes 0.1 or any number without providing further information. E. A process of the sequence dominated the idea of limit in the E-group, compared to an object as the limit of the sequence in the K-group. About 30 % of E-speakers conceptualized the idea of the limit in the sequence as an increasing or decreasing process 105 without the limit. However, in the E-speakers, 29.5 % reported it as an approaching process to the limit. Both E-speakers (29.5 %) and K-speakers (27.8 %) considered numbers of the sequence as an approaching process to the limit. The limit of the sequence as a number (15.1 %,and 45.2 % in categories 4 and 5 respectively in Table 4.50) dominated the idea of limit in the K-group. 106 8282 o: :8 .:EM 8:05: 2: .:o :2: 2:3: 885:: x 8 .86 8:828: : 83 mom : ...H m + E: 82:22:. . 52:65 a w5:82&m v: a $2 oEM 878.65 w: 80 Em: 0:: :8 8828: m_ 80 8. 0:: 3: 8m 2:: m 558: _ :8: _ .:o 9 893:8 2 P8 x83 H 3308...: :0>0 Co 82 2am...o 2 m 85E m 8 .m . . . :Ex 2 mac woo.— 2::8.:: :82 88: EB 8.: :5 _ ::: c 88.59:. 3 : :om m+ 2:» »_::_:E.: _.o :8B2 a o:_:> 8:: .o 9 80m x m< $2 8.9 8E: 2: 2.8.: 8:8 : :82 8>o::._ ::: o m:8B3 81820:— P: 8m 2:82.56 8 :82”. macaw m_ 0::; £5 6 9 8cm x m< W2 2:! 0:0 :82 88: EB 7:528 :82 88: EB a 888m 3: now “:0 2:8 :o 4882.832382 85:28 6 8 8cm x 2 :12 «EM : 8:2: 3.838 88: ::: .:EELE 338958 0: 88B? :_:oB : F: 8m o 8>o o .:o ::o: a 8.: 888: 0:: in: 8:; :o :82 «::o :0>0: :8: _ .::0—:9: £8: 3 : 828 ::: c 8 .820 2 a ”ma :5— 2.8:: ::: 0:0 8 282° 8w EB 8:: ::: 28 9 282° 8w EB a F: ::m S: ::o 858 8:“... m + mm .58 beg—:8 :::: 3 E8: 33 :5— .-Mmme 89:5: :28 a :3 o:_>_::8ww_: flow A 8:98 8% a m< mm: ohm o. 8>o _ 8B :...m::m_:o_8 8:2..88 o. 8ow x m:::: .: S m. ::M : w:_:82 8>a:...:E:_8 A :_ 5:2 0:: ::: 5:38 a 0:: E EuN mm: ::m _.o 3:2 8 : w:_:82 “:0::B .::2 0:0 :82 322878058: 0:: 8 :E: 2: 88:2 :3 m + mm in: .3 58:80:»: 2: 3:22: :9: 8:3 82 8v. m_ 8:: 8:: 5:2 0:0 2 .820 8:88: 2:. .28 8:82am: a 2 E : ::m _.o 9 $828 : 8.: 28B _ ::o 8E8 ..o .22 93:80:.— o:_m> E 88205 :8 .:E_8: : m :8 8:. : 8: _ ::::o 8E8 o 8>o o «o ::o: m .o 8:823: x m< 3N: nov— 8w2£ 8 8:58: 88: 250:0 :: 3.8388 F: :8 “.::0 :o> 8: ::m ........... _. .:mmmmmmmmn...w..mmamemE-mlummflwww..m.wwflfiflmfimwwmw ::o “:6: 8 282° ::: 88.0 wflmmwdw. :2: .m 8:. mm 82: x :8: 39:2: _ ::88828: x 888m EN: 8v. 38: 0:0 2,: ::: 28 8 .82: ::: 2820 chow :o 38: 0:0 3:... 3: 8m 2:88:28 0:: w:_N=m:o:2 :3 E 838 :mM 8:05: BECE :m 8E 52:8 2 282° wE8w 8.2.8:: E6: EoN :2 :mm _ ::: o 8 cm 8:2: 84... _.o 8 80m 8:: ::: o 8 80w :::. PE :3. _. 9 :: :::8...E:oEa 2_:c:_ 38. 0:88: :5. .o 2:80: EB x HE 0mm .820 0:: E5: :8058 Hm:a:_:oB : ::: 28 :8058 :_:oB 0:0 8:... H8 8:595... 5.: m8: “.:oB : .o 8 .820 2:08: EB x m< 83 :mi . . . :mm 5.0 9 8.www.mmfiwmewww..flwmwfi 88:8 oaoooo. 83E “.::_:0B 8:: ommwwwmdmwdmmw :8 o 9 82c 8an0: x 28:5: 0:: 8 8302 £958 Am WE :mM 8 08: EB : 3:83:03: .28 E5: :8 28 :8038 :::ow 8.: 7: «mm 8:28—80 52B 8 8:2: _ _:::_:.: :::—:28 ...x 0:: “Eon ::: 88 m_ ::éEcE :Bo: 22B _ EB :3 58.—”:::: ::: 885.88: 822: :2 NEE: x02 88 _ TVS :NM B05. :8: _ 2...: 8m :0>0: .785 ::: .bEcE 8 ow :8: FEE. E :vm 11mm.au“gamwmmmmmmumwflumflam.afifimfiqfiawlmamvwm. 1-1—1.. .mmw. o o: 8 macaw 8:95: Emtoo : 8 :0:.Emlmmlmwflndwmflmmmw EB 8B8: 0:: ...o 8 2:8 0:: 8.: 8889:8828: x m< 7.8 «NM 8>o:...:u:2 0:0 9 08 8:8 0:: ::: .28 88.: 9 80» 0:0 HE ovm _.o 8 820 ::8 m_ 8:25.: 2: .o 8 820 25 E6 :82 ::::8 88: w:_8w m_ x m< .:o :0>0 o .:o ::o.“ a o: 8 wEow fl 8B8: :::. RE F: ::: _. 88.58 EB 88:3 2: 28 8:88am: x 8 :::: of. HS :vm . 8 80 o wE8w 7 3 $5828 08 x o 8: :> o m H a 2M 22 8F: 8 mfiowxcmmmwux 8|:H1.EB.::E:_8 _ o _ . . . . : u _ :u < 3 SV— ::88 0:: .28 8:82 “.:8: :5 8:28 w:_8w.:=E:_8 x H: 3m $38 8:: mo 85:38 0:: E :22 :88: EB :::: :9» o: 8:? .> > :8: E 88:88 2:55 8 mo :8: 2: :88 8:81: 2: 9 8888M 3.: 28.: 107 Table 4.52 Distribution of the use of the limit of the infinite sequence Chi-square Students Processual use Structural use d f Value Sig_._ E-interviewees 90 % 10 % K-interviewees 15 % 85 % E-participants 75.8 % 16.7 % ... K-participants 33.3 % 63.5 % 2 60'62 '000 *Differences are significant (p S .0 I). Table 4.53 Distribution of the use of two columns Chi-scniare Students Separate processes connected processes D f Value Sig.__ E—interviewees 8O % 20 % K-interviewees 15 % 85 % E-participants 62.9 % 31.8 % 4 . . "' gparticipants 23.0 % 73.8 % 2 6 25 000 *Differences are significant (p 5 .0l). F. K-speakers’ discourse on the infinite sequence appeared more structural than that of E speakers. E-speakers used the infinite sequence in terms of infinite processes, whereas such reference was rare in the K-speakers’ responses. Instead, K-speakers explicitly referred to mathematical algorithms associated with the function of the infinite sequence. In other words, the K-speakers’ use of the sequence was structural rather than processual. The processual use of the sequence in the E-interviewees was related to either that the limit is unreachable or that it is rounding up ([1-5], [IO-12], and [14-18] for unreachability; [5] and [7] for rounding up). In contrast, the infinite sequence seemed to guide most K-interviewees to focus on finding its limit value according to known mathematical algorithms (“a form of 0 over 0” [22], “limitE” [23, 24, 27, 31, 33], “multiply m +5 ” [28, 30, 32, 34, 36, 38], and “use l'Hopital’s rule” [29, 33, 37]). In addition, most of the E-interviewees seemed to separate two processes in two columns (the x and function columns) of the table shown in item V (see [1], [3], [4], [5], [6], [7], [9], [12], [14], [17], [18], and [19]). In contrast, the task of finding the limit in the K- 108 LASE: mafi- iCt£ group seemed to make two processes in these two columns connected ([21-23], [26-29], [31-32], and [34-36]). Thus, when the question “What will happen later in the columns of this table?” was asked, the K-speakers associated numbers of the infinite sequence with mathematical algorithms. The chi-square results in Table 4.52 show a significant difference between the E-group and K-group in the use of the sequence. Chi-square analysis of the distribution in the use of two columns also indicates a significant difference between these two groups, as shown in Table 4.53. C. When finding the limit in a given infinite sequence, five routines were identified according to how to use limiting processes to find out the limit: 1. Describing a process by looking at patterns of numbers in the sequence: There were interviewees who looked at either increasing or decreasing patterns of numbers in the infinite sequence. They then endorsed that it was increasing or decreasing. Their discourse seemed to be mediated syntactically on the basis of changes of numbers in the sequence. 2. Describing a process by characterizing the given function: Some interviewees focused on a character of the given function, that is, that one divided by a smaller number was a bigger number. Then they concluded that the function kept increasing because x got smaller and smaller. 3. Finding the limit by looking at patterns of numbers in the sequence: Other interviewees checked the value which numbers in the sequence approached. When there was an approaching number, then they endorsed that the sequence approached the number. 109 C! rou TQM in L‘- PM; man CORE 4. Rationalization: Some other interviewees multiplied m + 5 to both numerator and denominator to find out the limit value in the infinite sequence. Afier calculating the limit value, they endorsed that it was 0.1, it converged to 0.1, or it got closer to 0.1. 5. l'H6pital’s rule: There were interviewees who seemed to first look at the function as a form of 0/0 when x approaches 0. Then they used l'Hopital’s rule to find out the limit value by differentiating both numerator and denominator. After getting the limit, they endorsed that it became 0.1, or that it converged to 0.1, or that it approached 0.1. 6. Unidentified: This is the case when students say 0.1 without giving a reason. 7. No answer Table 4.54 Distribution of routines in item V Routines . li-speakers . KO-speakers mtervrew survey InterVIew Survey I) Describing a process by looking at patterns of numbers m 20 % 27.3 % 0 % 1. 6 % the sequence 2) Describing a process by characterizing the given function 5 % 6.1 % 0 % 0 % jiggizg the limit by looking at patterns of numbers in the 70 % 50.0 % 25 % 44.4 % 4) Rationalization 0 % 1.5 % 60 % 41.3 % 5) I'Ho‘pital '3 rule 0 % 0 % 15 % 7.1 % 6) Unidentified 5 % 10.6 % 0 % 2.4 % j No answer 0 % 4.5 % 0 % 3.2 % H. E-speakers used routines based on processual use of limit. K-speakers employed routines on the basis of structural use of limit. About one third of the E-speakers in routines 1 and 2 of Table 4.54 and many E-speakers (70 % and 50 % in the interview and in the survey, respectively) in routine 3 appeared to employ their routines based on processual use of limit. In contrast, 48.4 % of the K-participants in routines 4 and 5 and many K-speakers in routine 3 used their routines on the basis of structural use of limit by considering the concept of limit as an object, that is, a number. In routine 3, only 34.8 % llO of the E-participants (23 students out of 66) seemed to report two connected processes in the use of two columns on the table in item V. In contrast, 53.6 % of the K-participants (30 students out of 56) appeared to present two connected processes in the use of the two columns. The following Episodes 7 and 8 are excerpts from the conversations with an E-pair and a K-pair respectively. These two episodes exemplify their routines and difference in the use of the infinite sequence. Episode 7. E-pair in finding the limit of an infinite sequence Speaker I90. 1 l9l.E5a 192.E5b 193.E5a I94.E5b l95.E5a I96.E5b l97.E5a l98.B5b 199.E5a 200. ESb 201. l 202. E53 203. ESb 204. E5a 205. ESb What is said What is done [show the card with “what do you think will happen later in the columns show the card of this table”] What about this one? What do you think will happen later in the columns of this table? Um... I said it would just approach point one Yeah this one would Yeah and that one would approach zero. Yeah. I’m guessing because it just keeps getting point 09999 Right. ' It’s just going to keep getting nines. Yeah. I think it’s gonna...it’s gonna approach zero from the left side the right sides gonna approach point one. Mm-hmm. Why? Because it’s just the way the trend is appearing to be this one keeps kind of moving over one decimal place well like every other one. And this one you keep adding more nines which means eventually it will have to run...round up so Mm-hmm. Because I don’t think they would make the answer point 099999 forever [laughing] so it would eventually have to round up to point one. Yeah [laughing] Sounds good to me. That’s what I though too. Episode 8. K-pair in finding the limit of an infinite sequence 71.1 72. Kla 73. Klb 74. [(18 75. Klb 76. [(13 [show the card with “what do you think will happen later in the columns of Show the card this table”) What do you think will happen later in the columns of this table? I looked at it only around here and I thought it is getting closer to 0.1 I simply thought. . .This [first column] is decreasing by less units from l...less and less...0.5, 0.1 and once again by a half of l ...0.05 and again 0.01 and so 5, l, 5, l separately like this...following the trend, I thought that x is getting closer to 0 more and more To 0 Yeah...so...this from 1 to 0...] thought the next one is going to be 0.0005 Yeah 11] 77. Klb It continues to go on like the rule. . .rule. . .anyway. . .because I thought x is decreasing in that trend, as a result, x is not zero but is going to get to a number that is close to 0. 78. Kla Yeah 79. Klb So if x is 0, this answer is going to be in the form of 0 over 0. 80. Kla Yeah 81. Klb As x is getting closer to 0, I thought that root x plus 25 minus 5 over x is getting closer to 0.01...ah, 0.1 82. Kla Uh 83. Klb Just exactly... 84. Kla Ijust thought...as the values of x are decreasing, [it’s] getting closer to 0.1 85. Klb Wordings seem to be just a little different. Item VI Item VI was designed to elicit students’ mathematical discourse on limit by asking them “What will happen to the curve when x approaches 0 from lefi or from right?” in item VI-a (l) and “What will happen to the curve when x goes to positive infinity?” in x 2 2 items VI-b (1x_) and VI-c ( x ). These three different fianctions and their graphs + x (1+ x)2 were provided in the questionnaire. Table 4.55 Distribution of endorsed narratives in items VI-a and VI-b E-speakers K-speakers Endorsed narratives Interview survey interview Survey Vl-a VI-b VI-a VI-b Vl-a Vl-b VI-a Vl-b I) It approaches 0 10 % 0 % 13.6 % 0.8 % 0 % 0 % 0 % 0 % 2) It is increasing (without the limit) 25 % 30 % 9.8 % 31.8 % IO % 0 % 4.0 % 5.6 % 3) It approaches an asymptote 10 % 0 % l 1.4 % 8.3 % 0 % 0 % 10.3 % 11.9 % 4) It goes to infinity 45 % 50 % 30.3 % 28.0 % 25 % 35 % 16.7 % 19.0 % 5) It diverges (to infinity) 0 % 0 % O % 0 % 25 % 20 % 23.8 % 20.6 % 6) (It becomes) infinity 10 % 10 % 26.5 % 17.4 % 35 % 35 % 35.7 % 39.7 % 7) Unidentified O % 0 % 6.8 % 6.8 % 5 % 0 % 7.1 % 0.8 % _8)No answer 0% 0% 1.5% 6.8% 0% 0% 2.4% 2.4% Table 4.56 Distribution of endorsed narratives in item V-c Endorsed narratives . E-speakers . 116-speakers interwew survey interwew SurveL I) It approaches 0 5 % 3.8 % 0 % 0.8 % 2) It gets closer to l 60 % 25.8 % 15 % 20.6 % 3) It converges to (becomes)! 10 % 16.7 % 80 % 68.3 % flit is increasing (without the limit) - 0 % 10.6 % 0 % 0.8 % 5) It approaches an asymptote 10 % 7.6 % 0 % 5.6 % 6) It goes to infinity 15 % 12.1 % 5 % 0.8 % 7) Unidentified 0 % 7.6 % 0 % 0.8 % 8iNo answer 0 % 15.9 % O % 2.4 % 112 I. VI-a: —l- . About one third of E-speakers in the first highest percentage responded “it x goes to infinity.” In the next highest percentage, the E-speakers (26.5 %) replied “(it becomes) infinity.” Other responses were distributed evenly among “it approaches 0,” “it is increasing,” and “it approaches an asymptote.” More than one third of K-speakers in the first highest percentage answered “(it becomes) infinity.” Other Korean responses were distributed evenly between “it goes to infinity” and “it approaches an asymptote.” However, only K-speakers (23.8 %) replied “it diverges (to infinity)” 2 J. VI-b: .112. . About one third of E-speakers responded “it is increasing.” In the next + x two highest percentages, 28 % and 17.4 % of E-speakers answered “it goes to infinity” and “(it becomes) infinity” respectively. Approximately 40 % of K-speakers replied “(it becomes) infinity.” However, only K-speakers (20.6 %) responded “it diverges (to infinity)” Other Korean responses were distributed between “it goes to infinity” and “it approaches an asymptote.” 2 K. VI-c: x 2 . About 26 % of E-speakers answered “it gets closer to 1.” Other (1 + x) responses were distributed almost evenly among “it converges to 1,” “it is increasing,” and “it goes to infinity.” The percentage of K-speakers who responded “it gets closer to 1” was smaller than that of E-speakers (15 % in the interview and 20.6 % in the survey). An overwhelming majority of K-speakers (80 % in the interview and 68.3 % in the survey) replied “it converges to 1.” L. The number of “no response” from item VI-a to item VI-c. The number of E- speakers who did not answer questions increased considerably from item VI-a to item VI- 113 c. Comparatively, the number of K-speakers who did not respond to questions remained at the same rate. 114 5:5 9:30: :30 050 2: J t 2: 50: 550:0: : 5:3 :62: :0>0 _ ::: 8— :o>0 — ::: 2 :0>0 _ 5 ”Emma: .: 3.. .::0. 8:050: 3:238 :0>0: 5: .508 A 2: 0: 88.0 ::: :30? Bow 2 3: :0m .33 2:8 2: 5 :05 02: lulu- 05 00m 0.». :35: m: 5 2: 25:00m v . :EM :::5 o>:: o: 3&0 80 5 £2 2: 50:: 0 =0: m< : com .lawl—Mmlamwmfl. aflwflmmwglz.flmfiwfl_aw x 3 H . 2:! -fiwmwdflwflmflmmgafiwafilmylmnfiwgflmwgmmwflmmfi.01: 8.: E555 582055A§53 5E: 58 a =: 820.». _ N . 3:0. 8:55: o :5 : 2: 0: 50 m.5...__:Em 35283 85003 = m . 50m ngmmmwiwol Ec:muwmuoimwdmwmmmEwwxwamwm.uwa:mwwfll1M.“ - :Ev. ,ill[imam—la::::.mmwmmvwMadam:wfidfiflflflfldflflflflfldfiq1m 1.- :0m 89:5: 555: : 5 :0:::2:5: ::: c 85085:: :5. 0 85050: :0>0: 5 =5 :2: 5 530 m 80. z m: Em 5:550:20 85:00:. . .:0_m8::xo wEoom .mm 59:» 2: :25. I: lllllllll ::: MwmmmflmwwdvfllmmmwiwlmmmElmmmflmwwmwmmwflwmm. w5uom .3 35:5 0: 8:85: 5 .::w: 50:... 850:0:::: H m< 88 ::x 95:5 u>::wo: 0: 0w ::: A. .:2 2: ::o: c 85085:: x m< Hm: ohm 95:5 0: 80m 20: E m: :: 5 0:2: 08:02: 5:8- 2: 30:0 :o>o 85:8 5 ._:0_to> 5:55: 2: :0 8w:0>:00 5 5.3882 25 m: 5:: :28 25 .: 3Q 0:05 ::: 0:05 w55003 5 8:07 85:55.5 50:03:: :2 E : nhm ................ lgfiflflflmmfi.mmmflfiwwwmmflmuwgwwm nov— ...-..--.llllll--..l-..:Wo.EJmNmm.Emmmhimawfimwflmmmmx.«dimmfiwfllcwm. x: :0 25? 2: 8:25. 8508: x :0 25:> 2508: 2: .: SN. 03: 5 82:5: 25:5 8558: : w5508: 5 5 6:8 50:05:: :0: m< 8: ::m 5 : 2: :: 500— _ 5 . :::5 855 ::: 5:5 :5 8:258: 550: 85085 :88: 5 5n :8 :5 ::o 7.35:5 85:: 0: 80m 5 .:2 50: 0:0: 85805:: x m< :8 58. 65.5 ::: m:0::0: ::::Em 0:5 8:0 823: 03 .0:0N 85:05:: x m< HE new 8:: 52:5 : :0: m 5 :5 ::: Ewabm : 305.: 85003 : SN: 5 880:0 :0 852.0: . . . . . . :3: :0>0: 5 :5 28:53: 52:55 : m: 20: 505% .:5::5 88:05:: 5 a :8: . 85:0: :5 50: 85...:30: 55:5 0: 80m 5 8820...: :0::5508: 2: m5cuw 885 5 .o 0: 88.0 w58w 823. x 8 .22: :0>0 :2 2: 50:: E :mm :_ .:5:::0”: : 5 53:25:: 2: om=:0on...o:_:> 23:25:80 2:: o .- l ......... 0 500:8 o :88 _ .: 55:5 5 5 Jaw: ::o: 85:05:: 5 h GE :3. 0:0: up :.::0 5 88:02: 0:3 :: .: 5 :3. 2895?: c: 2 0:2: 55:5 o>::wo: on 0: w50w M52: :2 ES: G: 0mm 35:5 3855.3: 5 o :0>0 _ 55:5 2 ::8 8:3 $3 53: 0:0: 50:0: :88: .53 53:85:: ms 3:0: : :0: 85m 2mm 55:5 8.: 8:258: ::: 352350555 5 .:0 595:: _ RE :mv— 85:5: :5: >82 : 3 855: 0:0 05:03...b_::5 :0:0:::< H2 :8 55:20:00 50:: 850:0: _ . 5 :: m5: :o::2xo:.om:|5wlo£ 5 5 5050: 950.00— :o:< .:5::5 035:0: Jaw: E0: c 85805:: T; .: ”NE an— :o>o 5:03 35:55::5 :0: 0m :23: 0: 8:05:53: ::o: 2.85:. 2: gm lxmmmmwmqmnfi$ 2: :0 :::—::::www.mflflmmmwmflmmmmwmafldmwflmmfii:.::lm _._l:d:im 0m 3 2:03 .mEUo: 2: ms 0m M5 :wmmmwlmmmflw—mmmm 2:..68: ::: .3 80m ::::w 2: :2: 0m Ema: 0a.: _...2::m :3 :NM :::30: :0>0: :5 w50w :80— m.5 85:8: 0:8 2: 2:03 55: of. 7; 05m. $3: 5 50:0: 2: :: o 0: :30—0 w5:|ow 82.5: o :5 : 5 8555: ::E: : :0>0 0:0 88:03...ng :5 85:02.3: :0>0 _ :0 5:0: : 82:55: 2:: ::3. 25 :::—3 83 o>::mo: 85:05:: 5 :2 2: ::o: 85:05:: 5 m< a 95m 95:5 5 o :u>0 _ ommmmmmmmflw 22 85:5: :omimE : up EB .2502: 0: 0w x :55: :3 :55: o5 ::o _ 25.: 2:: 2:5 8:2:8 55:. a: :_v_ .3 855: 0:0 88:8: 855: 52:: 0w :5 8:25 2% 5 m< E :vm 25m: 50:: :0 :2 .::0: o 85:05:: x m: o>50 2: 0: .:5:::5 :53 .:-:> R. :-_> :55 5 M .:0 55: 2: 50:: 8:83: 2: 0: 880:8.m 3.5 29:: 115 7.85555 5 w5ww:.: 5.. :0:.B 850005 5.8%.: 08:00m RE 02: 9 0:55:00 .50: .::5 9 50 5 885505: 2: ::: . 550:0: : 5 .::0. EB 05.8 2:...B0:w 9 m50w 5:0 0.: :0::50 ::: :0m 9 m50w 88:05:: 2: .x :5 885505: ::: 88:05:: 5:: w55>:0 .: RE 255 :0: 0.5 00. .5985 :0 :0B0: 05: ::5: 89:. 5 :9 :0 :0B0: 05.: Wm. 00m. 0.3: 9.258;. :08 00.: . H. E 55:5 8.: . :0>0 500.550: 55:5 08:00: 5.5.5. to 80m 5 $3 :0: 5:55 0:32 ::: 05: 3:51.:an 858822011559: 50 85005 .05: 9.2582,. 08 .5 55:5 9 80m x :25? SD 05v. :0555 m. 88:05:: 05:0 0050: 05: 080005 55:5 50:0: EB :. TH. 00m. :0m::. 5055 5 885508: .50 0050: 2: 08:02.38: 02 38 55v. 55:5 0558: m. a :05B :5 0m EB 55... Km. 50m. .55: 2:: s. 8. 3:. w=_ao__o::_...:_=:s m. 25 2: .5. 95: is: 2.: EB: 55.: 25:8: 9 o: :5 2:3 a: :m. 8: 5:5 9 80 x :5: 85:50: 0. x 08:005...x 5 :05>.: . 0>:: 2: 9: 29 5 8 :: 90:05... 50:05 0:: 58:05:: ::: 885508: .5 355:5 9 8905: 5 :3 55. 2: :::: :2.w:.. m. :9 2: 08:00: ::: 55:5 9 80m 5:05 005: . 8m. Em :28: 0. 58:05:50 2:: 080:05 08:00: 55:5 9 80m 9. SE :5. 55:5 0558: 9 80m A 55:5 0558: 9 80m x m< FE 0mm. ::: 5980 5... 9 8 :0>:00 :9::_50:0 2.: ::: $3.5 macs: 5....x 5.? 80.: £8 02%.: .8”. :8: :5 59:5 55:5 0:50:25: 2. =5 .3. £0 55:5 9 890.5: 5 ::0w::. 0.: T950555 0050: 08:00m $3 03. 55:5 95 080:05 52800 : 050005 EB 08.: 2. FE ::m. :58: : 8 50 8500 .::53xN .05: m._:5:8.[... 08 . 5. .50 5:5 0358 9 80 8500 55:5 :0>0 55:5 :0 5:0: : 55:5 9 80w x :05? We. 58. 5 8 0:: ::5: B0..0: :03 EB 01:29:55: 25:50 :: 0.5 08:00m. Ev. 5cm. iiixll:::-.----dtwflwxawwfiwwwwmmmflwmww:mmmmmmmmmfiunmwm». 5 50:9 :0 08:0 :0>0: A05: 55 5 50:91:55: 505:. . .29Emfimm :0w::50 2: 500.0050 . 55:5 :::B9 880:05 5 RE :3. 25:50 0.5:...:0w::. w520w :0 0:000. ::: .:0w::. 0:0w x 8: RE :0: 0:05 0: 05: :2: :0 .5 0. 0:05 a 05: 08:02. 5:5 0558 585508: 05:50 :2: ::5: :0w::. 2 8:80:05 88:05:: 05: :0 53. 9 0w .::0 B 52:08.5 20w a 83.5 20: 0: 8.12055 :8 5: 00.5 E. :mm 0::: 05... 55:5 9 8905:3555. 0358: 9 880:05 5 :3 :3. :0>0:0.: 0:05: :0 w50w 0:000. 5 05:35:55. 9 80m 5. FE 0mm. 3 :0>0:0: mw§| 0558: :::B9 0w EB 5...:28: 88205 88:05:: 05.: 80% 53. 0.: 55:5 :0>0 :05—::: 55:5 00.: 0.52.55c5 9 0m anB 5 RE 5mm. :2 9 :::5 0.5 0>50 05: :: w5500. 03:55.5. $2 :3. 83.5 m:.:0w.:5.::5 55 :055: :05—::: 55:5 08:00m SE :9: 55:5 :::B9 7:: 505:: m. m.55: ::: 83.5 m. 50.05000 .5. ”an. 59. 0:05: :0w :.:0B 5 ::: :0>0:0.: 55:5 50:05:: ...: 8:. gm. 1! lililxiux:Nmmmmmmwwmmwamflwflqfljmmmomma 1 ...... w aaammmfismluflmmflwmwaammmm.:Nmmwwmtflmmmflwflwmmmafi. 2: 5 :2: :::: :28: m. N :0 0050: 05: 5 “000:: w580:0:. Km. :9. 0w ::: :0 2.5500 EB 0>.50 2: “55:5 0558: 9 80m x :05? 3m. 05%. 55:5 9 8w:0>.: 535:::5 9 08205 x .5 .x+. :0 2:: 55. 2055058 25:50 :: 850:0:::::.5.::5 9 w50w :000. :83... En. 5.5m. 2:80:05 2: ::5: 0:05 0.. Nx :0 2:: MW580:05 05: 08:00m Gm. :.v. 8:020 850005 05. 0.5:. . .:0555: 8%.: : :550005 :0 0:000. : PM. :5: 555:5 0558: 9 80w 0: :05B PEG 2: 9 :0:::5 EB 853 .5-.> R+~ 55> 50: E In .50 :5: 2: 505: 20:83.: 2.: 9 880:8.m mmé 0.5:: N ”6 52888 2 :ofi:_Eo:u: ::: 8285:: : 2: a: 8202 _...:o_8:e 05 .«o :::: 05. . .88 8253 029.0%? 2:. . Aron—:::“ E @233: 3...»:0 E _ : «Ev. .8828: 05 285 8:83 2 8:9 :0>0: 2:3 0:0 885:: E3 = 33 wow 93:3. x 3 323m 3388:: :5 53250:»: 52. 50:0 2: 2 2.5— . 9 homo—o ESE—MEEEEM 05 :o 889:»:238w :82 33. F: :3 wow g 3 8 05 :::: :82»: Eaton 05 8:83 835:8:0: ::: 8.80:5: Son 83:: h 0:0 3 8w5>=8 : moo : 25. o 2 to cm 2:03 2 .5388 2: E bEcE win 33:8: :0» t 83 vom -lfiwemma.mgmwwwwmwwmwmgflmfimad.:ma- Us: Immaaxammwzmmm$3.28“:mmwwawawfléfiamm:::me 8: “2:22 me 852: Exam—:28 05....258» x .:So:o F338. Co: 39:83: 382.5: «335 82:28 r86 _ S: :E: a 22 z 32 pom 0%.: 2:38:22 : 250:» RE: QEM Emmfl 032mg .: 8:8; HmOEE Pa _ 2+5 ::: V; 82:55: 92 3:85 Go: «Ev. 9 wEow 2 x 8:83 EEcE 0228: on o. wEow 2 2E: 05 $8 _ :2 8m 5888:: E _+»N:.om:83 _ :::: m2: 2 2 Sn o:o 8:08: a 2 8E8 Son 3541' .823: 338% 95 839:8 ::o .:So:o 8585:: 25. Ho: as. A8» 25o 8:83 ::o a Boa—Emma :: 2 205. .._ 2 Ema—u flow a 83 2m 25 :25 ac 2mAmmwwwflmmwmwflammmmMam.mafia.afiflmfimmalim 2: 256598 ::: 05mm 2: 2 8:8: 3:83:58 2:30.: 75: 3.x :: 222: :8 :8 :o> ._ 8 80» A .bEcE 03:8: 9 Sam x 3 FE unm— OEO 0a 0 h0>=00 hOum—JEOEOU 0...: U5 hOuNhDEsc 0:”. Such— o:o :0>0 0:0 22 cm .83: m x :o>o :28 m x 2: 2 286508 3:83...~x 3 82m 58 223: C. :25: 85228 .32 So: SM 3.28.» 05:52? 35 :88 $5 {.8 2:48 B E: :::. ”FF ::: DE _ 2 898:8 2 Ewan: _ 8:.— 2 “86508 :08 8:83 Hmo: cov— 2 $80 :o>o:=_>1_ 5m .o:o no 028 A 88.5%. E? 350 of. mm: «Km :0 2:8 o .oo o E m a E8 8: 38 mm .8828: So ::_x...:oumE H _ m H _ ._ a. I; u _ To: fix who: _+xN ...BE:: own“. bo> a 8:589 x 85.105 8885:: 2 on new 0:0 2 28: 2: £56508 22: 2868 95:59:5— 8: So: 8x 0:0 :9: 58% 2:88 :0>0: EB 2 $255 0328: 9 meow 2 m< RE new w ...m a mm 0:0 283 :0>0: 8:0: _ on :8 xmmo 038 52885 xmo :8 m 2: :::: :o B 2:65 288 A 885% :k $25.25 3538 8885:: x m< :3 gm on ::: w:_m8._o:_ x no 89% 2: 3:83 ._ 8 893:8 : 33 an! -- . N «my Suggest Toww_£...o:o .::co A:8: 83: En 0:0 oESB 2.: 82 0mm 832w 283—: .258 05 z: :0 £8: 05 8:: ::: x n 023: 2:8 2 E283 05.208 on 55: :8 2 50:0 9 88.0 How :8 : S3 an :0» 30:» H ::::w 05 Set 832:. “mi. _ .::0 585% 2:03 : at nmm 4:20.226 Sn :::EV. 2 22:38:: m5 m 2 x .2 2 8323 oil :3 umx 08 ::::w ofito “:03 5:.Co n52 _ ED «mm 52: .:Ex :8 85533 2 _ fizg :0>0 _ 9:39 wfiow 2 : GE :9— 83:8 ow 8 wEow 22 3:83 DEE: 9 cm E? 0:: 25‘ FE 3m @23va 28: $228. . :::—Em Pa 80% @8882 22:. 33 mg 380.5 2: 5 £5.22 9 meow A 83805 a 3:803:58 oz 35 Sum 28 2 mo :0>:00 2 63: 23296:; 3:5,: 4:0 2:8 E28: 8 :8 :o 8:8: 06mm 2: mm: 2...:558 on: :o 8me bEuE :0>0 €5.25 .«0 ::8 m :5 mic: A: ::::w 29 “:3 _ 3.3 fiv— 52: a 22 3:83 805 How :0>0: F2 Sn T» 885% EB : WE nvm bEcE 8 wEow 22 “5:05 _ 58% 2: H: 9228— :32 33 2M Emmi 2:: m...~:o:oaxo 0:52:08 2 homo—o flow 983% 2.; EH :vm “$25.25 0328: 9 meow x :0:? 9:8 05 9 :88: EB 3:3 .95 ~93: 0-; Eu: 5 la mo 28: 05 Son: 8:81: 0% 3 momcommom omé 03:; N ”7 tor Table 4.60 Distribution of the use of the contexts in item VI Functions Students Processual use Structural use Chi-square . df Value S'L E-interviewees 90 % 10 % Vl-a _ K-interviewees 45 % 55 % x E-participants 72.7 % 25.8 % l 49.60 .000‘, K-participants 28.6 % 68.3 % E-interviewees 95 % 5 % Vl-b 12— K-interviewees 15 % 85 % 1+ x E—participants 65.9 % 27.3 % K-participants 31.7 % 65.9 % 1 ”'96 'OOO‘l E-interviewees 80 % , 20 % Vl-c x2 2 K-interviewees 5 % 95 % 1+ x E-participants 64.4 % 19.7 % ( ) K-participants 10.3 % 85.7 % 1 102.8 .000" Note. *Differences are significant (p S .01). M. The phenomenon first observed in [F] returned. Many E-speakers spoke about the limit of a function in terms of processes. Once again, the Korean responses were formulated in a more formal mathematical way with the purpose of finding the limit. The contexts, “x approaches 0 from left or from right” or “x goes to positive infinity,” directed almost all E-interviewees to use either geometric features on the graph (such as slope and asymptote) or algebraic properties (such as comparison of degrees and increasing rates between numerator and denominator). These contextual uses led them to a processual use of the limit. This processual use of the limit in the E-group ofien seemed to be related to unreachability in the limit algebraically or geometrically ([3-6], [8-9], [10-13], and [18]; [40] and [48]; [75], [80-82], [84-86], [89], and [91-921). Comparatively, the same contexts seemed to guide the majority of K-interviewees, with just two exceptions ([68] and [93]), to an algebraic reasoning to find the limits of three fimctions by using different mathematical algorithms ([19-20], [23-25], [27], and [29-33]; [56], [58], [61], [63-65], [67], and [70-72]; [94-95], [99-101], [104-105], [107], and [109-110]). When the question “What will happen to the curve?” was asked, almost all K- 118 interviewees took for granted the task of finding the limits, and then structuralized limiting processes with the concept of a limit. This difference between the E-group and K-group in the use of the contexts was also salient in written survey responses. The chi-square results in Table 4.60 show a significant difference between the E-group and K-group in the use of the contexts. N. In the task of finding the limit of a given function with its graph, eight routines were identified according to the aspects of limiting process and the limit that were used. 1. Describing the limit by looking at the graph: There were interviewees who looked at either increasing or decreasing features on the graph. Based on the graph, they endorsed that it was increasing or that it went to infinity or that it diverged to infinity or that it converged to one. 2. Describing the limit by looking at an asymptote: Some interviewees focused on an asymptote approached by a function or its graph. When there was a vertical asymptote, then they endorsed that it went to infinity. When there was a horizontal asymptote, then they endorsed that it approached the asymptote value. 3. Finding the limit by assuming that infinity is a number: Other interviewees substituted infinity for x to find the limit of a given function. Then, they interpreted infinity as a real number (e. g. 1/0 = 00 or one over an infinitely small number is infinity). For example, if the result after substitution was infinity squared over infinity, they concluded that it went to infinity because an infinity in both numerator and denominator was cancelled out. 119 4. Finding the limit by comparing increasing rate in numerator with that in denominator: There were interviewees who focused on a comparison between numerator and denominator to decide which one grew faster than the other. If numerator grew faster than denominator, then they concluded that it went to infinity. In the opposite case, they endorsed that it went to zero. In the case of l/x, because the numerator was fixed as one, they endorsed that it went to infinity when x got smaller. Also, if increasing rates between numerator and denominator were the same, they endorsed that it converged to one. 5. Finding the limit by dividing the greatest term in numerator or by comparing the greatest terms in both numerator and denominator: Some interviewees divided both numerator and denominator by the greatest term in denominator or compared the greatest terms in both numerator and denominator. Then they calculated the limit value of the function by direct substitution. 6. Finding the limit by using l'Hépital’s rule: Other interviewees seemed to first look at the function as a form of 00/00 when x approaches infinity. Then they used l'Hopital’s rule to find the limit value. 7. Finding the limit without specifying the method 8. Undefined: Other interviewees focused on the idea that the limits from the right and left were not equal and then endorsed that the limit did not exist. 9. Unidentified: This is the case, for example, when the student reported that it keeps going or increases with no other explanation. 10. No answer 120 Table 4.61 Distribution of routines in item V-a Routines E-speakers K-speakers interview Survey interview survey 1) Describing a process by looking at the graph 30 % 18.9 % 45 % 41.3 % 2) Describing the limit by looking at an asymptote 35 % 29.5 % 0 % 11.1 % 3) Finding the limit by assuming that infinity is a number 0 % 1.5 % 10 % 3.2 % 4) F indtng the limit by comparing numerator With 3 5 % 9.8 % 25 % 20. 6 % denominator 5) F mdmg the limit by dtwdmg the greatest term m 0 % 0 % 0 % 0 % numerator 6) Finding the limit by using l'Ho‘pital ’s rule 0 % 0 % 0 % 0 % 7) Finding the limit without specifying the method 0 % 12.1 % 0 % 4.8 % 8) Undefined 0 % 6.1% 0 % 0 % 9) Unidentified 0 % 20.5% 20 % 16.7 % M No answer 0 % 1.5% 0 % 2.4 % Table 4.62 Distribution of routines in items VI-b and VI-c E-speakers K-speakers Routines Interview Survey interview survey Vl-b Vl-c Vl-b Vl-c VI-b Vl-c Vl-b VI-c gngfb’bmg bb’bbb” by ’bbk’”g b’ ”be 30 % 25 % 23.5 % 12.9 % 10 % 5 % 16.7 % 5.6 % 2) Describing the limit by looking at an 20 % 40 % 16.7 % 22.0 % 0 % 0 % 4.0 % 0.8 % asymptote b) F‘bd'bg ”'3 "m” by “‘“m’bg ”7‘“ 20 % 0 % 1.5 % o % o % o % 0.8 % 2.4 % infinity ts a number 4) F'”d‘”g me I'm" by bbmbb’mg 15 % 20 % 10.6 % 6.1 % 6o % 3o % 34.9 % 24.6 % numerator with denominator 5) F‘mbbg ’bbbm" by d'v'd’”g ”"3 0 % 5 % 2.3 % 4.5 % 15 % 45 % 12.7 % 38.1% greatest term in numerator 6) Finding the limit by using l'Ho‘pital '3 rule Zefzzgm’he1"""W"”0“’spec’fi”"g’bb 0% 0% 6.1% 10.6% 0% 0% 5.6% 10.3% 0% 0% 6.1% 0% 15% 10% 3.2% 4.0% 8) Undefined 0% 0% 0.8% 0% 0% 0% 0% 0% 9) Unidentified 10% 10% 31.8% 29.5% 0% 10% 19.0% 11.1% 10) Noanswer 0% 0% 6.8% 13.6% 0% 0% 2.4% 2.4% O. In finding the limitbof l in item VI-a, dominant routines in both groups were based x on the geometric representation (i.e., routines 1 and 2 in Table 4.61). P. In finding the limits of the more complicated functions in items VI-b and VI-c, routines of E-speakers were based on the geometric representations, compared to those of K-speakers on algebraic representations. In other words, the use of geometric representations in routines 1 and 2 was still dominant in the E—group, whereas the use of algebraic reasoning (i.e., routines 4 and 5) dominated routines in the K-group. 121 As previously explained, visual mediators are visual means used by students for communication. In item VI, both algebraic symbols and graphs of three fiinctions were provided for limit-finding tasks. In calculating the limit of each function, different visual mediators between the E-group and K-group were employed for the sake of scanning mathematical context. Q. Syntactic mode in the E-group and objectified mode in the K-group. The first attempt in the responses of most E-speakers at scanning the written phrase of “when x goes to positive infinity,” involved uses of the shape of graphs and geometric mediators such as asymptotes and slopes. In contrast, the same written phrase was scanned as the algebraic expression of each function in the responses of about 60 % of K-speakers (see Table 4.62). The scanned processes in the E-group may be called syntactic mode, as it requires only knowing the written phrases and given geometric mediators. However, most K-speakers seem to make a transition from syntactic mode to a different mode for finding limits. In other words, they seem to reify both original written phrases and geometric mediators with the purpose of finding limits. The flexibility in the scanned process of the written phrases and given geometric mediators can be described as better performed than the less flexible syntactic mode because the syntactic mode allows for very little interpretation of the visual mediators and few predictions. The following Episodes 9 and 10 exemplify differences between E-group and K- group in finding the limits of three functions in item VI. Episode 9. E-pair in finding the limits of three functions in item VI Speaker What is said What is done 146. I So, [show the card about item VI-al what about this one? What show the card happens to the curve as x approaches 0 from the lefi or right? 147. £70 The curve goes to zero. 148. E7d The curve goes to neg... [both say “oh”] [laughing]. I was gonna say negative infinity, but that’s 0. 1 don’t know. 122 I49. 150. 151. I52. 153. 154. 155. 156. 157. 158. 159. 160. 161. 162. 163. 164. 165. 166. 167. 168. 169. 170. 171. 172. 173. 174. 175. 176. I77. 178. 179. 180. 181. 182. 183. 184. 185. 186. 187. 188. 189. 190. 191. 192. 193. 194. 195. E7c I E7c I E7c I E7d E7c E7d I E7c E7d I E7d l E7d l E7c E7d I E7d l E7c l E7c E7d l E7d 1 E70 E7d E7c l E7c E7d l E7c l E7c l E7c E7d E7c E7d l E7d 1 Well, yeah it’d go, yeah it’d go to negative infinity and this is the asymptote would be 0. [...] So... So because? It depends on if you’re looking at... Mm—hmm The y axis or if you’re looking at the x axis. Mm-hmm But it says x Yeah as x approaches 0 from the lefi, so as x goes to 0, y will go to negative infinity. Mm-hmm Because? Because there’s an asymptote at 0 and it doesn’t cross it. [. . .] It just keeps getting higher and higher and higher but it never touches 0, so Mm-hmm Uh, yeah the x coordinate would be... Mm-hmm close to 0 Mm-hmm Mm-hmm But the y y coordinate is gonna be infinity. It’s like the same, that right, negative infinity. Anything else? No. [show the card about item VI-b] What about this one? show the card As x goes to positive infinity, um, y goes to positive infinity. [..] Because? Um because here as x goes on to infinity, the y goes up to infinity, and gets closer to infinity. [. . . .] Yes, I agree both goes to infinity and because the t0p is higher than the bottom Mm-hmm So, it’s just going to keep becoming a larger number. OK, [...] anything else? Do you want to add? Um, it looks like...isn’t there an asymptote here at negative 1? It looks like. Yeah, so um but this one for this side um, it doesn’t go to positive infinity, it goes to negative 1. So, oh never mind [laughing] But, you know, when x goes to, you know, positive infinity? But... Yeah there’s an asymptote at negative 1 and whatever [....] Do you want to add something? Oh no [show the card about item VI-c] What about this one? x squared over 1 show the card plus x squared? As x goes to positive infinity Mm-hmm positive infinity. 1’ goes to 1 That’s what I said, it gets closer to 1, you can see that there would be an asymptote right here. Yeah And that would be at 1 Can you explain why? Because of the way that these both curved Mm-hmm 123 196. 197. 198. 199. ' 200. 201 . 202. 203. 204. 205. 206. E7d E7c E7d I E7c I E7c l E7c E7d E7c They’ll end... [...] Well And here, there’s an asymptote at one, I think. Mm-hmm [ ...... ] That’s...that’s what I have, y equals 1 as x goes to infinity...positive infinity Do you want to say why? Um, basically the same thing that you can tell there’s an asymptote here. Mm-hmm And it doesn’t cross it, 1 was looking at the equation but I can’t figure out why Yeah Yeah Episode 10. K-pair in finding the limits of three functions in item VI 191. 192. 193. 194. 195. 196. 197. 198. 199. 200. 201. 202. 203. 204. 205. 206. 207. 208. I Kmf Kme Then...|show the card about item VI-al let’s solve the next problem. What show the card happens to the curve as x approaches zero from left or from right? [.....] When approaching from the right, the curve infinitely upward grow toward plus infinity... Um...um... When approaching from the left, the curve toward minus infinity infinitely. ..it does not intercept y axis. ..I thought it’s going to that direction. The reason is. . .? [...] in 1 over x. . . in 1 over x because it’s not 0 but approaching plus 0...from a number which is a little bigger than 0...so it’s positive...so it’s growing to the upward direction on x axis...if plugging in 1 over 10 and 1 over 100 and 1 over 1000, it continues to increase...by becoming 10, 100, and 1000. . .Considering that way, because I thought that it’s becoming infinity...without intersecting with y axis...because it’s not 0. I also thought the same way. So...because it continues to increase by plugging in 1 over 10, 1 over 100, and 1 over 1000. Yes [show the card about item VI-b] When x goes to positive infinity, what show the card happens to the curve? [...] I thought that this one is similarly going to become infinity. Here now what he and I said, speed which is similar to ratio comes out. . .Because the increasing speed of the numerator is bigger than the increasing speed of the denominator, the disparity between numerator and denominator is going to become wider by plugging in [numbers] Um...um If this disparity decreases, it’s converging. Because the disparity increases, 1 think that it’s going to diverge. Thinking so is okay, but...that x grows to positive infinity means that [x] equal to 0 doesn’t need to be thought. Because x equal to 0 doesn’t need to be thought,..that...thinking that x is not 0. . . .if dividing this numerator and denominator by x, the numerator is approaching l infinitely and the denominator is going to positive infinity because x is positive infinity....if by doing so, I think that it can be more easily calculated Instead, are you saying that x goes to infinity? Yes [show the card about item Vl-c | When x goes to positive infinity, what show the card happens to the curve? As I said before, the difference continues to decrease. The difference between numerator and denominator is big at first, but as x increases, the 124 difference is decreasing. 209. I How did you know that the difference is decreasing? 210. Kmf By plugging in [numbers]...continues to do ...the difference continues to decrease little by little. 211. I Please tell me concrete numbers? 212. Kmf Yes. At first if plugging in 1, it comes out 1 over 4. 213. I Yes 214. Kmf Because it’s 1 over 4, the difference between 1 and 4 is 3 215. I Um. . .um 216. Kmf If plugging in 2, um...it comes out 4 over 9. But ...this one becomes 5. 217. l Um...um 218. Kmf Just if continuing to plug in [numbers], because 1 finally thought that this difference is going to decrease little by little... 219. 1 How do you think? 220. Kme As I said before. . . .uh. ...that denominator. . .so in the status that numerator is fixed, if denominator is increasing infinitely or decreasing infinitely, while thinking that value is approaching 0, both denominator and numerator were divided by x square. Then it can be calculated as in the case of the previous one. 221. I So, what’s your answer? 222. Kmf One 223. Kme One Item VII In item VII, the question “What happens if you continue increasing the number of sides of a regular polygon inscribed in a circle?” was asked with the following concrete geometric representations in Figure 7. Figure 7. Geometric representations provided in item VII Table 4.63 Distribution of endorsed narratives in item VII Endorsed narratives E-speakers . I(.-speakers lntervnew survey 1nterv1ew Survey I) It approaches the circle 55 % 48.5 % 15 % 38.1 % 2) It gets closer to the circle but never reaches it 25 % 7.6 % 0 % 0 % 3) It converges to (or becomes) the circle 20 % 28.8 % 85 % 57.1 % 4) Unidentified 0 % 9.1 % 0 % 4.0 % 3N0 answer ' 0% 6.1% 0% 0.8% R. The majority of K-speakers reported that they accepted the endorsement that the geometric sequence of polygons became the circle, compared to less than one third of E-speakers. Only 28.8 % of E-speakers reported “it becomes the circle.” 125 However, an overwhelming majority of K-speakers (category 3: 85 % in the interview 57.1 % in the survey) replied “it converges to (or becomes) the circle.” 126 __> all." a." ......._L I ..._ —...r—..LUU.:._ ”Ln-pvuxrtur— -::ZHFJL L: :::. 9.: 34:3... 33:23:? 3.: Nu.- .I..J.f.:avnN./..Jv~ TC.? “:::.5 =35 622:5 2:002. 2020 2: 223 =0 3 0>0E 250: w532m 3.3:: 3:002. 50.0.20 3 050002 0: m50w 0.: Hon. .::0. :0: .30 .23 8.550 combo: 2: 23 0.020 2: c0250: :03 2. ... 8m. :0m. ”Emwamflnmmawfl.§§- 10:222-? 656321522222022.22220.302.521.0122. 2: ...o 02.5. “23302:: $200025: 03 0,220.20 2:95. 2E. Em. 25. a: ::0 How 33 22.20220: 2: .20 0223:2020 2: .20 303 02... 3.. 00m 12 0: $902.00 303 2:: $25.5 8 000» = 02:2. m< Fm. :Ev. 0.020 3 0n b.3293: :0>0: ::: .2020 0 0n «::ow 2230.05. :25. 5: wow l.m.m:m_...s.m.mw§mazmmfiflwaflwmmmflwmaammmm 226 a 3 26 2.12.226. awdagmwmmmflfim. 208.0 2: .2 7223.220 032. 00:22: 2.: ..0..3Em 2.... En. 05v. 3 2:300: £05m .20 2025:: 022:5 .3 223 0.2.0 3 2. ...3 25.. 2. .r 2. 00m. 023m 2: 0 :0>0: :03 2 H: ...0 :0 00.0 9 .000 0 .3 208 0 0.020 3 05002. :2: 2.0:: 50: 3 925002. 3.20 2:. .2. Wm. 22v. 050002 2:03 0.02” 2: .20 W03 2: .2.“ 2mm: “.2: :0 303 “5:32.: 3“. 20m 0.020 m 8:800: 2 ow .o 9 0 0:0 3 952000 0 208 0 wE 0w...0 0:0 0 0 0 .2: 30.3 $0 _ . $902.00 :03 €3-20050n. 2.: 5025.25 0320:. m05m m. rem. «Ev. . . . a a . .2 . . 2C :. . A m. 30m. 0.0.20 0 35002. 2....»2225 0: 000w 2 2. Hmm 25. 0.020 3 22000: 2:03 2:30.03 .20 25053 025.22 .3 03 22.qu Em. -immmwwm.wamowm.mflmfiflmflfi1:.1m.m..m01312wm5..-0lmmm.n..lfiolmmmam.- 35. _:-1ll&mm.mw.:i.:!0.mw....wflm.:22:me H. wwwmfiafiunmmvdmflmmcl $1.13; 05m. 2 0: 0902.00 0: 2202 0.2.0 3 0: :05 08.0 0.00. combo: 2: .20 :03 2: 3.: Ew:0_: . .230... m2: 3 920.00. km E m. 2:03 2 ::: .2020 3 2:33 2 £03205 85m .20 2025:: 2: m< mm 2 sum l.-52.251319..wwmw..2...Him.mma.m.m.m..:1.:...1 w...:1.-.mmmammmmwmflmfldfimawfl :3. .1.1-1.-.----I.-----E-...:l.mm..umm..zu.ozwdm.1m..mEmmwmwdmmmmw-wmflflmwwmmmm40 10.2. 0.00: . .2. .:EN 2 H2225: 0 :0. 0.93 2: .282: 08:03 03 .2. 8m. 03. 92.9 0:.:0>...m05m :0 .::053 0W3. 3025.25 .3 050002 2:03 2 E 2 35m. 2020 2: .20 303 2: 005000: 2.: .m2 :5: :3 23 22.0 3 0: 08.0 .05220 3:. 2 0.2.0 3 2. .3300. 03 m. 3223.: 05 0.2.0 2: :222: 2.032 8.3220235 >2 EN. 23. 2:03 2 .2020 3 00... $5002. 2 205 2: E3 :0» 85m 20E 2. 2. 8.. pom. 101.w.2..:0:m91mww:m.m.101wm.1m0wmmumuflwmmwmm...wmflmwzflwmammmqbanwfl 38. 0.2.0 3 05002. :0>0: ...: . . 20:25 20W303 F0032: 2. ... 3. «cm 0.020 3 350002 2 .052 03 2.0220: 2:02.285 2: :0 2:22 ,,i.-.-.-.iwm.wm.w £1: «mmvflmmlwmmmmmlmm.mM5.imwmw--. .memmm.m.w...1....lm: 2: 033.002350: 3 0.3 :08 2. 3.32205 :30 8:3 2: 203.. Pm. Dov. 2.22.2203 3.020 0.5 35.2.».2: 3: :2 :20 :2: 23 . . 33. 20N 3.30.3... 222.—.323 0m :0w F2532: 2: 25:28 2:00 :03. F. 0mm 03200: ...3 m2: 2 2: 23 0.2.0 2: 0.020 0 005002. 2 0.5.: . .223 M3,: 20: . 0m .m05m 20052. .303 320.22: 0...... .2020 2: 8 208.0 05002. ...3 2 Gm. 252:. :0 2022.0: 3 00... 35. 8.02032020 3 00... 205 23 20.2 3. 2mm. 2me. 23. 0.2.0 3 05.000: 230 2 ::o 3 050002 ...3 2 .:0w-x 0.: 5 55:5 0: 8.6.3205 x 0m:300m Wm. :92 0.2.0 3 00... 205 .23 205 0.00....m05. 0:2. :0 20. M22: 0m::00m 5 «mm. .2020 2:... .::5 05002. .23 03205 0: 8:52.00 .62: 2. g. nav— m05m 983.3 222: 3:000: 2020 2: : .E :0>0: ...:0> v 2.26 a :6 €22: -.---i--..-.m22222:2.222-220.2253:...:mammm.§.m_.-mmmfl 2: 02. 2 :50: 3 3 2005 2 2 $530200: 2 303 02300m 9mm. 3N2 2:802 2020 3 0n :0>0: 2:03 ::: 0.0.20 3 00... 0.00. 2 ::2 :23 2 a 0%. 0.2.0 3 520.: 2:03 x2._0> 2: .2205 303 02$53E§2 352 :0 .8020 2.30 :0» ::m .2020 2: .20 30.3 .23 205 $3200: 003% .0920 2.: £03222 x0t0> m< RN. :3. 2: 9 2.0.3230 80:23 02 ...2 2.0220: .20 02m 2: 223205 .2 3. 5m. 2020 2: 0. 08.0 222% 03 :2: 32: 0m 0.03205 m0x020> SN. 2020 3 023.0 02 2:22:03 2 ::o .2020 3.2 0 303 50 05% . . . 2v. 0. 2 0m:...0.020 3 205 050002 P2 22% 2: $3205 :0: 04. E 2%. 5:032 30 53. xm 2.0.020 0 5 .022285 :0 .0 3.: 2 3 .20 0.0.20. .20 2022:: 2: 5320 5 0:52.00 :0 .220 3232325 :> 802 5 0.0.20 3 5 20222022 mcowbom 3.:w2 .20 2:2. 2: 2:02: 20:00:: 2: 0: momcommom :9: 05.0.... 127 A» I. -\ - ...?» l... . "In... c: 3M Table 4.65 Distribution of the use of the limit in the sequence of regglar polygons Chi-square Students Processual use Structural use d f Value Sig._ E-interviewees 65 % 35 % K-interviewees 15 % 85 % E-participants 60.6 % 33.3 % 1 .2 .012 K-participants 48.4 % 50.8 % 6 6 *Differences are significant (p S .01). S. The same as [F] and [M] above. In the case of regular polygons inscribed in a circle in item VII, the context of increasing the number of sides of a regular polygon in the B- group seemed to be used only for its geometric features. Such uses of the context can be evidenced by the utterances of either increasing sides or decreasing areas (see “sides” [1 - 4, 6, 10, 11, 13-15, 18] and “lines” [15, 18] for increasing sides; “area” [7, 9, 16-17, 20] for decreasing areas). These geometric uses of the context appeared to direct them to think about a processual use of the limit of regular polygons ([1-12], [16-17], [19], and [20]). This processual use of the limit often was related to unreachability ([1-2] and [18]). In contrast, almost all K-interviewees continued to employ structural uses of limit. In the same context, many K-interviewees characterized mathematical features of polygons such as the lengths of sides, vertexes, and triangles ([27], [35] and [38] for the lengths of sides; [21-22] and [39] for vertexes; [29-30] and [36] for triangles). This structural use of the limit was related to reachability, that is, the sequence of regular polygons became the circle ([22-25], [27], [29-30], [31-35], and [3 7-39]). However, this difference between the E-group and K-group in the use of regular polygons did not appear clearly in written survey responses. The chi-square results in Table 4.65 show little difference between the E-group and K-group. T. Two routines for finding the limit in item VII were identified in the interviews and the survey: 128 SE1 'm 3‘; 1. Describing a process by looking at patterns of regular polygons in the sequence: Some interviewees focused on the idea that the number of sides was increasing or that the areas between polygons and circle were decreasing. Then they endorsed that the sequence of polygons was getting closer to the circle. 2. Finding the limit by looking at algebraic features of regular polygons in the sequence: Other interviewees considered the concepts of limit with limiting processes of regular polygons. As for the concept of limit, they used the ideas that the length of the sides became a point (or zero), or that the number of sides went to infinity, or that the difference in area converges to zero. Then they concluded that the sequence of polygons became a circle. 3. Unidentified: This is the case when students said that it approached the circle or that it becomes the circle without giving a reason. 4. No answer Table 4.66 Distribution of routines in item VII Endorsed narratives l3-speakers . K-speakem lntervnew survey 1nterv1ew Survey 1:)0 ggztbmg a process by lookmg at patterns of regular 0 % 56.1 % 0 % 31.0 % 25:11:33; :Smn by looking at algebraic features of O % 20.5 % 0 % 49.2 % 3) Unidentified O % 17.4 % 0 % 19.0 % 5) No answer 0 % 6.1 % 0 % 0.8 % U. Routines in the E-group were based on syntactic mode of regular polygons, compared to those based on their objectified mode in the K-group. The majority of E speakers scanned the written phrase of “increasing the number of sides of a regular polygon” and then they used geometric features such as the sides of the polygon and the areas to give an answer. Comparatively, after the majority of K-speakers scanned the same written phrase, they focused on algebraic features of geometric mediators such that 129 84 the length of sides converges to zero or that the number of sides went to infinity. The former discourse in the E-group seemed to be mediated syntactically on the basis of changes of regular polygons in the sequence, whereas the latter in the K-group appeared to be based on its objectified mode. The following Episodes 11 and 12 exemplify differences in their routines between E-group and K-group in finding the limit of the sequence of regular polygons in item VII. Episode 11. E-pair in finding the limit of the sequence of regular polygons in item VII Speaker 301 302. 303. 304. 305. 306. 307. 308. 309. 310. 311. 312. 313. 314. 315. 316 317. 318 Episode 12. 183 184. K5a .1 Bob Eob an Eob an Eob an Eob an Eob an Eob an . Bob I . Bob .1 What is said What is done [show the card about item VIII What about, you know, this one, using Show the card the sequence, the square, pentagon, hexagon inscribed in the circle, what happens if you continue... increasing the number of sides of a regular polygon inscribed in the circle Alright, 1. .. Explain your reasoning. I thought about this one in geometrical terms, which 1 don’t know why I switched up right here, but I said that the difference in the area between, like, the area of the square in the circle and the area of, like, pentagon circle, the area, the difference in it would become smaller. But I don’t think that’s the... I said... direction I should have gone [laughing] in. I said that... It doesn’t make... There would be less area, less, or less area inside of the circle, like, I meant, like, pretty much exactly what you just said, I just said it a little differently. Ok, we both thought about it, like, geometrically yeah, like, like, this area decreases each time, like, the area between the outside of the shape, like, outside... Yeah of this sided figure and the circle just decreases, so every time you add another line so it’s getting closer to becoming... a circle the circle yeah. [...] So what-what-what’s your final answers? That the area of the figure and the area of the circle would become closer and closer to each other, but it would never be the same. K-pair in finding the limit of the sequence of regular polygons in item VII Then [show the card about item Vll] examine the sequence of the Show the card square, pentagon, hexagon, heptagon..., which is inscribed in the circle. What happens if you continue increasing the number of sides of a regular polygon inscribed in a circle? Explain your reasoning. close to the circle...if it goes to infinity, we can say that it is the same as 130 the circle. 185. 1(5b So, the meaning that the sides are increasing is that the length of the sides is getting shorter. Later the sides can eventually be seen as a point. Then, a circle is originally the collection of points in the same distance. Then, from the center, because the lengths of the inscribed polygons are same, it becomes a circle. 186. 1(5a Yes. Item VIII-b 131 088800 0: :8 m .::0 2:8 05 : :08: E030: :0>0—:5: 882% 0: 002200 0: m20m m: a 88 :00B:0: 8:0:0t_0 0:03:20: 22:00 a :0:: :82 2 2:2 0 .= 8.; mom - 2253:8888- . ~22 20:23: £88800 7:0 ::0 =0 :00B:0: 88:22: 05 .: H03 Wm“ m 0: 820 30E:c2 80w 2 m 8:000:30 82. E F: 00m 028 23:00 0 8:08:00: E .mB0:m : 8 an .:0 8:068 02 E 8 2 022 E 0:80: :0: E m :0 :08 «::ow ME 852.: 0: 0:0 : 0: to 80m E 3: 00m A: 8 82028 E 5222 80280: = =0:B .: u =0 5.: PM: 222 02:: 05 m: A: a 2205: 05:20:05: 0 .3 0.50: M: E a 00m A 0: 820 w230w ...: 02B0: M20» 0:: 20:22 80:2 Gm: :22 “0:0 :.:E=0B ::: 8:20: 2:: 88208: :0>0: EB 00:068. 0::. G: :om llllll:-.1--Mam:..w_|mw:x_.mmm-mwmmmfloxwmmmmmmwwmmmmmmwwfiam- 02v— -l..--1l--llm.wm._mmmmmmm0 0: 9330 EB E. .m 0: :0w :0>0:: EB E W a 00m 0:0: m 0: :8 E a. 8:000:mm0 A: :0:2:: :0 8:268 02:0 028 0:: 58032200 88082 : 2 $3 :3. 0:: 0: :820 ::: :820 80w E ::: E 82000: 38:00 :0>0: E F: Em m :0: ME 2: m :0: w20w m.E....€:c2 2 : .m u :0 2.: ”mm as. _E0:0w 2 E2: 0 8 m :0 0:0 EB 8:268 0::. mm: 00m— 028 22:00 0 0>0: EB E :0:: :050258 m .05. .E :08: :0>0: EB E S: 8:25: 0 0: .0w :8 E W: .282 E .0:0:0:0:H .8w:0>:00 :0 52:2: 0: 80m : E2: 3: 32 00v— . . . . . . ::m m 0: 8w:0>:00 =0 $22.22 0: 80w : EE: m< :3 0:2 0: 32200 :0>0: 2: 882:0 EB E :0:: 8:23: 0: H E 2 0mm . 2 :02: :0 8:20: 20:00 0 0: 2 :0>:00 :0:E0 2 $02.3va E2: 0 0>0: E8: {.800 20:22: :0 00:068. 0. . 20:02: E23 .m 8:23: 28:00 .0 8 820 w28w 2 :0 888:02 : m< 82 ::M 0 a: 020> x3885: 0. 20¢ w2::028 £08: 2 E2: < Ho: :2“: m 0: :820 w28w E :0 2:0: _0:0:0w 0:: 88082 : m< EN: no! 808 E 0:0:B...m 8:22 :0:: 8:08: E :2: a: 80m 008.68 0: 6 H3 mom a 8:250: :82: 8>02 E .mm .mm ..0 :EB 032200 0B : $3 :3: 0:0: 2 8. :0 02:22 :08: 0.:0B E ::: m 0: :820 .0w 3 M: T: unm ..l-1.m_1 “flammanflmm: a 2. . .m B20: 8200.: 2 00M0mw8 0: .E. PM: 0.3: :0:afimflmmrxmm101—mmmagmaflnwwmwmwmaxmwxflmmwxmmmwANHr 08 82000 :0 8 :820 38208 30w E $28882 2 00:068M5: SM n. :038 E28 2: 0: 820 30:22.2 20w E 3: :mm m 0: :82m-wm._:.mm0:wm. :mM 0:.0N 0: :0>0 C60 E Sm .Sooo :flmm:0.m-mmm.mz&.:.mwxm- 2 88.68 0:: :0 20:22 0:: 002:2 0: 28 2 : :0:? Wm: 03. m .::22: 0 8.20:: 8:80: 22:2 020 cm :0: EB 8:268 :::... 5 «mm a: 0: 0: w20m 2 H80 0E:B_ :0:2=: :08 2 8: E 0:0:B :20: 0:: m: m 32:2 :0: 8.: IL 00202 0:: d: 00220 2 20220 522.2 0::.E .008: :0E< F8 :Nx . . gm llxwmmwmwmwmmwflomxflmdwwfllfiflmy:.::E..m:::::r0.m..&m:lm.:.odlm..w_. .xlulwwmwmam.flmwflmmm:m”.....quflUMfl.mmmmm:mmmmzmmwlmmmmmmnwm $250028 PE ::::w 0 02:5: 2 2:0: :EE:c2 .:0 020> 0::. RN: 0N2 :0>0:0.: :0 w20m P: .m 2260 E2: 0:: 52:2 8:000:30 a: m< 5 0E: n: :0:2:: 28:00 0:: 0: 8 :0>:00 2:0: 80:0 :0:: :0E0 250: 8.20:: .... E A8868 2,5020% 8: _ :05 80. 2 : 0:0: 05 :0:? HNN: :8 < 0: 00m :0» 00:0 .820 E8: 2: n— :8 < :08: :0>0: :8 :0> Hm: :vm m 0: mmwmwflaw. : _ v— m a: n: .Ufio Cd Mfim>wfi ma. . .:oUv-U0fiE: wCMSHOEOm mm 5w2¥fiEm1~ : NH N —V— 2 OH O war—NU “SD 2 SUNOH M GNU hODE—a: vac: Hfia Nfim 0:82 22 800 2:3 n: a: ..0 00:268. 0 .:0 E2: 05 2 m 8:20: 0:: :0:: "”220 20:58 < .:-=_> 95> ::0E 2 8:86 0:: 8 82:080.”: Sea 2:06 132 Table 4.68 Distribution of the use of the limit P in a sequence Chi-square Students processual use structural use d f Value Sig:_ E-interviewees 80 % 15 % K-interviewees 30 % 70 % E-participants 40.2 % 5.3 % ,, K-participants 11.9 % 45.2 % 2 62'76 '000 *Differences are significant (p S .01). V. E-speakers’ responses were relatively consistent but not in tune with the canonical interpretation of the word limit. K-speakers’ interpretations were more diverse but often consistent with the canonical interpretations. The majority of E- speakers used expressions such as “approaching,” and “getting closer to” to explain the number P is the limit ofa sequence ([1], [3], [6], [8], [1 1-12], [14—16], and [l8-20]). K- speakers’ responses were diverse. However, they often made utterances saying that the sequence an converges to P as n goes to infinity (see [25], [29-34], and [37-38]). W. E-speakers provided processual explanations. K-speakers spoke about the limit P in structural terms. In explaining the meaning of “P is the limit of a sequence,” most E-interviewees’ responses referred to the word limit as processes in their definitions. This processual use seemed to be related to only sequence processes of an without considering processes of subscript n. The processual use often was connected with the idea of an asymptote ([3], [7], and [8]). In contrast, most of the K-interviewees focused on either a general term an or a relationship between two terms at first. Then either this general term or a relationship between two terms was characterized by specific mathematical features. The chi-square results in Table 4.68 show a significant difference between the E-group and K-group in written survey responses. X. The idea of reachability in the K-group and the idea of unreachability in the E- group. This processual use in E-group was often characterized by unreachability to the 133 limit P ([1-3], [5-8], [1 1-12], [14-16], and [l9-20]), that is, “P is the limit as an unreachable process.” Comparatively, the K-speakers’ ideas of “P is the limit” were dominated by the idea of reachability ([21-22], [30-32], and [37]). Y. E-speakers formulated interpretations in their own words. K-speakers used more formal mathematical formulations. Many K-speakers clearly made a relationship between the two processes of an and n in the limit of a sequence. In order to define “P is the limit of a sequence,” they often provided formal languages such as “converge” and “limits” (“converge” [21, 22, 31, 32, 37] and “limits” [33, 37]). The following Episodes 13 and 14 exemplify differences in defining that P is the limit of a sequence a], a2, a3,. .. between the E-group and K-group. Episode 13. E-pair in defining that P is the limit of a sequence a], a2, a3,. . .(item VIII-b) Speaker What is said What is done 145. I [show the card about problem VIII-b] What about this one? A show the card student claims that a number P is the limit of a sequence al, a2, a3, What does this mean? 146. Eoe Uh, it, this, uh, personally I interpreted this as, you know as, a1, a2, a3 it just keeps rising to a4, a5, etc., and it’s, slowly, or quickly, approaching P, whatever P might be... 147. Eof Yeah, no matter what the value of the, of a is going to continue to approach P ‘cause P is the limit. 149. 1 Is there anything else you want to say? 150. Eoc Not really, I mean that’s- 151. Eof Yeah . 152. Eoe This based, um, you know everything I’ve done on that’s just my understanding of what a limit is 153. l Um-hmm 154. Eoe You know, numbers rising like that, it just approaches P. lts, it gets infinitely close to P. 155. 1 So do you, uh, understand the infinitely close to P? What he just said? 156. Eof Yeah, uh-huh. 157. 1 What is the meaning of infinitely close, to you? 158. Eof It means that, like, if you never actually touch P, never actually reach P, but it’s going to keep approaching it, no matter how big a gets, it’s going to keep going towards P. 159. I So do you agree with mainly what he said? 160. Eoe Yeah, more or less. 161. 1 OK 134 Episode 14. K-pair in defining that P is the limit of a sequence a], a2, a3,. . .(item VIII-b) 175. I Then [show the card about problem VIII-bl A student claims that the Show the card number P is the limit of a sequence. What does this mean? 176- Kmd In this case, I set up an expression in the same way (lim an = P ) 177. I Then what is the meaning? If you explain the meaning more... 178. Kmd Um...so...seeing on the graph...no...rather than in the graph, when this becomes a... .. when n becomes infinity, I thought the meaning of that it converges to a number P...ln case that graph is painted like that [root shape]. ..like the previous problem, it can converge to 1...] thought so , [laughing]. . .yes, I thought so... ‘ 179. I What does the word “converge” mean concretely? 180. ch lt approaches a certain value. 181. Kmd approaching as close as possible 182. ch If put 0.99999 as 1 equally, like that....the same as approaching endlessly 183. I How did you explain this? 184. ch I just. . .sequence...in the sequence...in the sequence of an, as n grows, it approaches a certain value and considered an example. 185. I What kind of example? 186. ch So, if there is the sequence of 1 minus 1 over 11 187. l Um. . .um 188. ch As 11 grows endlessly, the value of sequence approaches 1. So, like that. Summary: Discourse on limit Table 4.69 summarizes salient characteristics of the colloquial and mathematical discourses on limit in the E-group and K-group. Table 4.69 Salient properties of E-speakers’ and K-speakers’ discourse on limit Item: topic Aspect E-speakers K-speakers A Limited' Both groups used the word limited in any version mainly in non- ' ' mathematical context. Among K-speakers the phenomenon was stronger context of use than among E-speakers Both groups used limitedCOH in the sense of finite (not infinite — Sbfilgt‘tf: something that has an upper ::::fi::::;: hmuedKMa'h m the Item 1: bound) or restricted — one that ' Creating could be larger. ..- sentences C. Limit: Both groups used the word, in whatever its version, in both With given context of use mathematical and non-mathematical contexts words Both groups used limita,” to K-speakers used limitKMwh mainly in denote an upper bound — expressions that were formulated as a D. Limit: something that does not let a textbook instructionto do something. type of use thing or process to get larger or as textbook definition. In general, It seemed that K-speakers were not very proficient in creating sentences with llMltKMafh. Item V: A process of the sequence An object as the limit of sequence Finding the E. V: Limit ofa dominated the idea 0f ”"1”- dominated the idea of limit. The limit limit Of an sequencer—mm”- AbOUt 30 % 0f E-speakers of the sequence as a number I35 conceptualized the idea of the dominated the idea of limit in the K- limit in the sequence as an group. increasing or decreasing process without the limit. E-speakers used the infinite K-speakers explicitly referred to sequence in terms of processes mathematical algorithms associated infinite F. Use of with the function of the infinite sequence sequence sequence. In other words, the 1(- speakers’ use of the sequence was structural G Routine When finding the limit in a given infinite sequence, five routines were ' identified according to how to use limiting processes to find out the limit H Use of E-speakers used routines based K-speakers’ routines were based on ' . on processual use of limit structural use of limit by considering routmes . . the congpt of limit as a number. About one third of E-speakers More than one third of K-speakers in in the first highest percentage the first highest percentage answered 1. v1-3; l responded “it goes to infinity.” “(it becomes) infinity.” However, only x In the next highest percentage, K-speakers (23.8 %) replied “it the E-speakers (26.5 %) replied diverges (to infinity)” “(it becomes) infinity.” About one third of E-speakers Approximately 40 % of K-speakers responded “it is increasing.” In replied “(it becomes) infinity.” J- V”): the next two highest However, only K-speakers (20.6 %) x2 percentages, 28 % and 17.4 % responded “it diverges (to infinity).” 1T); of E-speakers answered “it goes to infinity” and “(it becomes) infinity” respectively. About 26 % of E-speakers An overwhelming majority of K- K Vl-C' answered “it gets closer to 1.” speakers (80 % in the interview and ' 2' Other responses were 68.3 % in the survey) replied “it x distributed almost evenly converges to I.” Item VI: (1 + x)2 among “it converges to 1,” “it is Finding the increasing,” and “it goes to limit of a mfimty.” , - The number of E-speakers who The number of K-speakers who dld not given , , , , function L. The rate of dld not answer questions respond to questions stayed in the “no response” increased considerably fi'om same rate. item Vl-a to item Vl-c. M. The Korean responses were formulated in a Many E-speakers spoke about . . phenomenon . . . . more formal mathematical way With . the km“ of function m terms of . . . first observed m the purpose of finding the limit. [F] returned processes. In the task of finding the limit in a given function with its graph, eight N. Routine routines were identified according to the aspects of limiting process and the limit that were used. 0. v1.3: 1 Dominant routines in both groups were based on the geometric x representation P. Vl-b and VI- The use ofgeometnc . The use of algebraic reasoning representations was $1111 . . . c d . . dominated l'OllthS 1n the K-group. ommant m the E-group. Q Visual The scanned processes in the E- Most K-speakers seem to make a Nfediators group may be called syntactic transition from syntactic mode to a mode, as it requires only different mode for finding limits in knowing the written phrases and items VI-b and Vl-c 136 Item VII: Finding the limit of the sequence of regular polygons inscribed in a circle R. Limit of regular polygons reported “it becomes the circle. givemmetric mediators. Only 28 8 % of E- speakers An overwhelming majority of K- ' ,, speakers replied “it converges to (or becomes) the circle.” S. The same as Geometric uses of the context appeared to direct them to think Almost all K-mtervrewees contmued [F] and [M] about a processual use of the to employ structural uses of km“ 111 above . . the same context limit of regular polygons . Two routines for finding the limit in item VlI were identified in the T. Routine interviews and the survey Those of K-speakers were used on the n: basis of objectified mode. In other ' Routines in the E-group were Item VIII-b: Defining that the number P is the limit of a sequence a], 82, 83,... U. Use of . words, they seem to reify both original . based on syntactic mode of . . routine re ular 0' ons written phrases and geometric g p y g ' mediators with the purpose of finding limits. E-speakers’ responses were K-speakers’ interpretations were more V. Interpretation relatively consistent but not in diverse but often consistent with the of limit tune with the canonical canonical interpretations W.Use of limit interpretation of the word limit. E-speakers provided processual K-speakers spoke about the limit P in explanations. structural terms. This processual use in E-group The K-speakers’ ideas of “P is the X. Idea of limit was often characterized by limit” were dominated by the idea of unreachabiligr to the limit P. reachability. Y. Definition of E-speakers formulated K-speakers used more formal limit integpretatlons in their own mathematical formulations. wor s. 137 CHAPTER V SUMMARY, DISCUSSION AND CONCLUSIONS This study sought to describe characteristics of university Students’ non- mathematical and mathematical discourses on infinity and limit using the communicational analysis framework. The primary motivation for this study was the difference between Korean and English speakers when it comes to the relation between their non-mathematical and mathematical discourses on infinity and limit. The mathematical words for infinity and limit in Korean are different from the Korean colloquial words that correspond most closely to the English colloquial words infinity and limit. It is known that colloquial uses of mathematical words influence students’ mathematical discourses featuring these words. It was thus likely that mathematical discourse of E-speakers would be influenced by their colloquial discourse, whereas it was likely there would be no comparable influence of the colloquial discourse in the case of K-speakers. In other words, it was expected that there would be differences between K- speakers’ and E-speakers’ mathematical discourses that could be ascribed to this difference in colloquial influences. In order to better understand possibilities about the specific sources of differences in mathematical discourses of the two groups, students’ backgrounds which were likely to influence their mathematical discourses on infinity and limit were also investigated in this study. The research questions were as follows: 0 QUESTION 1: What are the relationships between colloquial and mathematical uses of the English words infinity and limit?; What are the relationships between colloquial and mathematical uses of the corresponding Korean words? 0 QUESTION 2: What are the similarities and differences between native-English and native-Korean speakers in their previous mathematics education 138 experiences, their learning habits and curricular experience with the words infinity and limit? 0 QUESTION 3: What are the similarities and differences between non- mathematical and mathematical discourses on infinity and limit of native- English and native-Korean speakers? The setting for the study was a calculus class for university students in the U.S. and Korea. Methodology involved surveys and interviews. The results of the study derived from two types of analyses: analysis of response patterns of the survey participants and detailed discourse analysis of interview transcripts. The survey responses were then re- examined to help validate findings from the interviews. A total of 132 English speakers and 126 Korean speakers participated in the survey. Within each linguistically distinct group, twenty representatives were selected from the survey participants for follow-up interviews in pairs. The detailed discourse analyses of the interview transcripts generated preliminary hypotheses in the interviewees’ discourse on infinity and limit. Overall analyses of response patterns involved searching for frequencies and percentages of the survey participants’ responses and comparing the proportions of the two groups through chi-square analysis to confirm the emerging hypotheses. Data from both sources were used to elaborate and verify hypotheses. Detailed findings are found in chapter 4. This chapter presents a summary of the detailed findings. Summagy of Findings Questionl: What are the relationships between colloquial and mathematical uses of the English words infinig and limit?; What are the relationships between colloquial and mathematical uses of the corresponding Korean words? As explained in Chapter 3, the relation between the colloquial and mathematical words in the two languages can be presented as follows: Infinitygcon = InfinityEMath, Whereas InfinitchOn #5 InfinityKMam 139 LimitEcOu = LimltEMam, whereas Limitxcon i LimitKMmh The equality symbol ‘=’ means that the words sound the same. InfinitchOn and LimitKCOu signify the colloquial Korean words that can count as rough translations of the colloquial English words InfinityEcOu and Limjtgcw, respectively. IrrfinityKMaflI and LimitKMath do not have any previous meaning in colloquial Korean — they are words of Chinese origin. Therefore, there is a discontinuity in Korean and a continuity in English between the colloquial and mathematical discourses on infinity and limit. K-speakers have little experience with the colloquial Korean use of the mathematical terms infinity and limit, whereas E-speakers do have experience with the colloquial use of the English words infinity and limit. uestion 2: What are the similarities and differences between native-E lish and native-Korean speakers in their previous mathematics education experiences, their learnin habits and curricular ex erience with the words in ni and limit? The second research question about students’ backgrounds is: What are the similarities and differences between native-English and native-Korean speakers in their former mathematics education and curricular experience with the words infinity and limit? Similarities between the two groups relative to previous mathematics education experiences, learning habits and curricular experience with infinity and limit To analyze different levels of Students’ former education with infinity and limit, course and content variables were considered. In the course variable, students’ recollections about their first experience with infinity and limit in a mathematics course were analyzed. Even though some E-speakers and K-speakers reported that they first heard the words infinity and limit before 7th grade, the majority of the participants recalled their first experience with infinity and limit in a mathematics course between 7th 140 and 12m grade. According to the results of t-tests, there was no significant difference between the E-group and K-group in the range of grades for first experience with infinity in a mathematics course. This result may indicate that students in both groups first learned about infinity during similar time periods. The survey included a list of seven topics related to infinity and limit and asked students to indicate whether they had learned about these topics. A chi square statistic was used to test for possible differences in the percentage of students who reported having learned the seven topics. According to the chi square analysis, there was no ‘ significant difference between the E-group and K-group in their reports about having 7 learned the following six topics: ‘infinite process,’ comparison of infinite sets,’ and ‘infinitely small or infinitesimal’ in the case of infinity; ‘limits to infinity,’ ‘limit of a function numerically,’ ‘and limit of a fimction geometrically’ in the case of limit. These results (especially with the comparison of both infinite sets and limit of a fimction used in the survey) can support comparability of these two groups. In terms of cunicular experience with infinity and limit, the majority of students in both groups (88.9 % of the K-speakers and 86.4% of the E-speakers) took either a pre- calculus or calculus course in high school. Students in both groups also reported that they listened to teachers’ lecture-style presentation in their classrooms for more than half of the lessons. These are important similarities between the E-group and K-group for comparability of these two groups. In addition to examining students’ former mathematics education and curricular experience with the words infinity and limit, other aspects that were likely to influence their mathematical discourse on infinity and limit also were investigated in the survey. 141 These aspects are Students’ self report on their experiences of learning mathematics and attitudes toward mathematics. Both the K-speakers and E—speakers reported that they listened to teachers’ lecture-style presentation for more than half of their lessons. Neither group reported small group work occurring very much. Overall mean scores of both the K-speakers and E—speakers in their attitudes about learning mathematics and the role of mathematics in their lives were higher than a neutral response. These results imply that students in both groups showed positive attitudes about learning mathematics and they also agreed on the need for mathematics in their lives. Diflerwces between the two groups relative to previous mathematics education experiences, learning habits and curricular experience with infinity and limit The survey asked about when students were first introduced to the concept of limit and infinity. The mean of the E-speakers’ responses about the grade level at which they were first introduced to the concept was significantly higher than that of the K-speakers in the case of limit, indicating they were first introduced to limit later than the K-speakers. As for course sequences taken in high school, almost all K-speakers reported having taken Mathematics 10 (for 10‘h grade), Mathematics I (for 11th grade), and Mathematics 11 (for lZ‘h grade) course sequence through integrated curricula. In contrast, most E- speakers reported having taken a course sequence in which algebra and geometry are separated. There was a significant difference between the E-group and K-group in self-reports about having learned the following four topics related to infinity: ‘infinite decimal fractions,’ ‘infinite sequence or series,’ ‘sums of infinite geometric series,’ and ‘countable and uncountable sets.’ The percentage of the K-speakers who reported having learned each of the four topics was significantly higher than that of the E-speakers. In the 142 case of limit, the percentage of the K-speakers reporting having learned related topics was significantly higher that that of the E—speakers in the following three topics: ‘lirnit of a sequence or series,’ ‘limit and the definition of continuity,’ and ‘limit and the definition of derivative.’ Interestingly, the percentage of the E-speakers, however, is significantly higher than that of the K-speakers in the topic of ‘the 8-8 definition of limit.’ These results indicate that the K-speakers seemed to have had generally more opportunities to learn concepts related to infinity and limit in high school than the E-speakers. E-speakers reported that they used a variety of textbooks in high school, beyond the representative examples provided in the survey, whereas many K-speakers replied that they studied from one of the seven textbook examples, and in some cases more than two. That is, there was considerable variation in the textbooks that the E-speakers used in high school, in comparision to consistency in the textbooks used by the K-speakers. Due to this complexity, it was clear that analysis of textbooks, as a possiblemeans of illuminating the different discourse experiences of students, would not be a productive endeavor., student representatives were selected and interviewed in terms of their high school textbooks instead of analyzing their textbooks. There were differences in the two grops in their descriptions of how they studied calculus. During interviews, K-speakers reported that they had systematically planned study methods and periods of rest and followed that plan. In contrast, E-speakers seemed to have planned less and did not follow it too tightly even if they had a plan. Even if these responses were from a very small sample of students, they suggest that K-speakers more carefully organized their studying and they devoted more time to it than E—speakers. 143 lust n and mar 5177. dis 6”. of l res] eler con [mi subs rtpc Question 3: What are the similarities and differences between non-mathematical and mathematical discourses on infinity and limit of native-English and native- Korean smakers? The third research question about students’ discourse is: What are the similarities and differences between native-English and native-Korean speakers in their non- mathematical and mathematical discourses on infinity and limit? Similarities between the two groups relative to non-mathematical and mathematical discourses an infinity a. Discourse on infinity - Non-mathematical uses of infinite, infinity, and infinitely No systematic similarities were found in the non-mathematical discourse on infinity of both groups — Only E-group actively used the noun infinity. - Mathematical uses of infinity The mathematical discourse on infinity of both groups was not yet well developed, in that it was quite different from the canonical mathematical discourse on infinity. In the mathematical discourse on infinity, the following common characteristics in routines and endorsed narratives were observed in both groups. Set-comparison routines: Many respondents in both groups made non-canonical choices of routines for comparison. Some respondents in both groups compared the sets with respect to the size of corresponding elements rather than with respect to the amount of elements. In addition, there were respondents in both groups who produced two contradicting answers as the result of applying two different routines of comparison. Endorsed narratives: Many respondents in both groups endorsed the narrative “A proper subset is smaller/has less elements than the whole set”. K-speakers were more likely to report that they accepted non-canonical properties of comparison. 144 b. Discourse on limit - Non-mathematical uses of limit and limited Both groups used the colloquial words limited and limit in both mathematical and non-mathematical contexts. The adjective limited was used in the sense of finite or restricted to describe something that has an upper bound or one that could be larger. The noun limit was employed to denote an upper bound — something that does not let a thing or process to get larger. - Mathematical uses of limit In the mathematical discourse on limit, the following common characteristics in routines and endorsed narratives were observed in both groups. Limit-finding routines: Many respondents in both groups made non-canonical choices of routines for finding limits by looking at their graph. There were also some respondents in both groups who found limits by assuming that infinity is a number. Endorsed narratives: Some respondents in both groups endorsed the narrative “limit is an upper boundary”. E-speakers were statistically significantly more likely to report the non- canonical property of unreachability. Dzflerences between the two groups relative to non-mathematical and mathematical discourses a. Discourse on infinity - Non-mathematical uses of infinite, infinity, and infinitely E-speakers had a relatively well developed non-mathematical discourse on infinity, which seemed to be building on their non-mathematical uses of the words infinite and infinity. The adjective infinite appeared mainly in the phrases “infinite number/amount of. . .,” as a descriptor of sets, signaling these sets’ large dimensions (see the property [B] 145 of infinity in Chapter 4). The noun infinity appeared mainly in the context of processes that do not end, as the target-point which these processes never reach (see the property [C] of infinity in Chapter 4). K-speakers’ non-mathematical discourse on infinity seemed less developed. They used the adjective infiniteKMmh in non-mathematical discourse as descriptors of objects known for their large size or of spiritual matters — not of sets or processes (see the property [B] of infinity in Chapter 4). They did not use the noun infinityKMam at all. When asked to use the non-mathematical version of the noun, they converted it to the adjective infinite. When given the mathematical word for infinity, they turned it into adverb infinitely and used it in conjunction with many (infinitely many), as a descriptor the cardinality of sets (see the property [C] of infinity in Chapter 4). - Mathematical uses of infinity There were several differences between mathematical discourses of the two groups in terms of use of words, routines, and endorsed narratives. Use of words: There was not much difference between E-speakers’ mathematical and non-mathematical use of the words infinite and infinity — they used the adjective with relation to sets and they used the noun within the same phrases reporting on unending processes: “goes to,” “continues to,” etc (see the properties [G], [O], and [R] of infinity in Chapter 4). In contrast, K-speakers’ mathematical discourse on infinity was quite different from their non-mathematical discourse. In their mathematical talk infinitelwmh, which appeared not very frequently, was used as a descriptor of cardinal numbers. The word infiniO/KMafi; appeared only when explicitly mentioned in the question, and it then was used within the phrase ‘goes to infinity’, which also appeared in the question. It was 146 not elaborated. In K-speakers’ mathematical discourse, there was almost never any reference to processes. The discourse used mathematical vocabulary and was structural rather than processual (see the property [T] of infinity in Chapter 4). Routines of comparison: One of the findings was that E-speakers’ choice of comparison routine was sensitive to the wording of the question and, more specifically, it depended f on whether they were asked which set was bigger or which had more elements (see the .i property [N] of infinity in Chapter 4). K-speakers’ choice of routine did not change with wording (see the property [M] of infinity in Chapter 4). Another finding was that the '. majority of E-speakers employed infinity in conjunction with an infinite process to compare two infinite sets. K-speakers’ talk about infiniO’KMam in their comparison routine was more formally mathematical (see the property [R] of infinity in Chapter 4). The other finding was that E-speakers tended to claim that two infinite sets are always equal. K- speakers relied more strongly than E-speakers on the narrative that infinite sets are incomparable. Endorsed narratives: E-speakers formulated interpretations about what infinity is in their own words. Their responses were relatively consistent and in tune with the canonical interpretation of the word infinity. In contrast, K-speakers used more formal mathematical formulations about the concept of infinity. Their interpretations were more diverse and often inconsistent with the canonical interpretations. They spoke ahnost exclusively in structural terms (see the property [S] of infinity in Chapter 4). To sum up, E-speakers seemed to be quite proficient in the non-mathematical and mathematical discourse on infinity (e.g, they were able to answer questions using their own formulations, different fiom that in the question itself). Their mathematical use of I47 di for be: Com the words infinite and infinity was not much different from their non-mathematical use. Routines of E-speakers were sensitive to the wording of the question. The majority of E- speakers employed infinity in conjunction with an infinite process to compare two infinite sets. Their endorsed narratives were relatively consistent with the canonical interpretation of the word infinity. In contrast, K-speakers’ discourse on infinity was more formally mathematical and structural, but they were not yet very proficient in this discourse — in their responses, they Ir . . ~._ I tended to use phrases that appeared in the question. The mathematical discourse on infinity of K-speakers was quite different from their non-mathematical discourse on infinity. In the use of word infinity, there were few references to processes. Their routines did not change with wording. Comparison routines of K-speakers were more formally mathematical. They endorsed narratives exclusively in structural terms. b. Discourse on limit - Non-mathematical uses of limit and limited K-speakers’ non-mathematical discourse in limitedmam and limitmam seemed less developed than that of E-speakers’. They used the adjective limitedKMmh in non- mathematical discourse only in the sense of extreme which was not observed in the use of limitechOu. They used the noun limitKMad, mainly in expressions similar to a textbook formulation (see the property [D] of limit in Chapter 4). Generally, K-speakers seemed to be not very proficient in creating sentences with limitedKMam and limitguam. - Mathematical uses of limit The mathematical discourse on limit of E-speakers was. not yet well developed. In contrast, K-speakers appeared to provide more developed canonical mathematical 148 discourse on limit (see the property [V] of limit in Chapter 4). There were several differences between the mathematical discourses of the two groups in terms of use of words, routines, endorsed narratives, and visual mediators. Use of words: There was little difference between E-speakers’ mathematical and colloquial use of the words limited and limit — they used the adjective in the sense of finite and they used the noun to denote an upper bound. E-speakers’ use was processual RJIA and they often spoke about limit as unreachable. K-speakers, in contrast, spoke about limit in structural terms. This structural use of limit was often related to the idea of limit P.’ as a number (see the properties [F], [M], [S], and [W] of limit in Chapter 4). In general, they used more formal mathematical formulations. Limit-finding routines: E-speakers’ choice of limit-finding routine was based on a processual use of limit. K-speakers’ choice of routine was based on a structural use of limit by considering the concept of limit as a number. Routines in the E-group were employed on the basis of syntactic mode of context, as it requires only knowing the written phrases and given geometric mediators. Routines of K-speakers were used on the basis of objectified mode (see the property [U] of limit). Finally, the majority of E- speakers used geometric representations to find the limits of more complicated functions, whereas K-speakers employed algebraic representations with algebraic reasoning in their routines (see the property of [P] of limit). Endorsed narratives: E-speakers formulated the idea of limit in their own words. Their responses were relatively consistent but not consistent with the canonical interpretation of the word limit. K-speakers interpreted the idea of liMitKMath as an object by utilizing formal language as well as formal mathematical representation. Their interpretations 149 were more diverse but often consistent with the canonical interpretations. They used more formal mathematical formulations about the idea of limit (see the property [V] of limit in Chapter 4). Visual mediators: E-speakers used a syntactic mode as they scanned processes for finding the limit of the sequence of regular polygons inscribed in a circle. K-speakers seemed to make a transition from syntactic mode to a different mode for finding the limit (see the property [U] of limit in Chapter 4). To sum up, E-speakers did not develop canonical mathematical discourse on limit. i They provided processual explanations of the noun limit and seemed to be quite proficient in this discourse (e. g, they formulated interpretations in their own words). They often spoke about limit as unreachable. There was little difference between E- speakers’ mathematical and colloquial uses of the words limited and limit as a process. Routines of E-speakers in limit-finding tasks were based on a processual use of limit. These routines were often employed on the basis of geometric representations. E- speakers endorsed narratives in their own words. Their endorsed narratives were not consistent with the canonical interpretation of the word limit. Visual mediators of E- speakers in finding the limit of the sequence of regular polygons were used syntactically. In contrast, K-speakers used limitmam in non-mathematical discourse only in the sense of extremity which was not observed in the E-group. In the mathematical discourse on limit, they spoke in expressions similar to a textbook formulation. They appeared to provide more developed canonical mathematical discourse on limit than E-speakers. K- speakers’ choice of limit-finding routine was based on a structural use of limit. These routines were often employed with algebraic representations. Their endorsed narratives 150 were more diverse but often consistent with the canonical interpretations. Visual mediators of K-speakers in finding the limit of the sequence of regular polygons were changed fi'om syntactic mode to a different mode. Discussion of Findings . Reasons for Differences in Mathematical Discourse on Infinipg and Limit There is one main difference between the E-group and K-group in their discourses on infinity and limit. The main difference is in their processual and structural uses of infinity and limit in the E-group and K-group respectively. In the E-group, the use of infinity and limit as process seems to be related to the processual use of the words infinity and limit in mathematical discourse. Due to the processual nature of the colloquial uses of infinity and limit in English, the mathematical English use also seems be processual. This may be evidence for a connection between colloquial and mathematical discourses on infinity and limit. It seems that E-speakers build on their everyday experience with colloquial discourse in developing their mathematical discourse on infinity and limit. In contrast, K-speakers’ non-mathematical discourse in the Korean mathematical words infinity and limit is rare and less developed in their own formulations. Their uses appear to be formulated from textbook treatments? or definition. In the mathematical discourse on infinity and limit, their language is more formally mathematical and structural. Their mathematical discourse on infinity and limit is more consistent with, and. possibly developed from, the structural discourse of mathematical textbooks, perhaps due to lack of proficiency or experience with these words in their non-mathematical discourse. As a’matter of fact, the nouns infinity and limit in their mathematical versions are rarely used as themselves in colloquial Korean. In addition, the more rigorous structure of their 151 definitions may be additional evidence that these students were introduced to the discourse on infinity and limit through mathematical definitions taught at school rather than through non-mathematical use. There is therefore a clear disconnection between K- speakers’ mathematical discourse on infinity and limit and their non-mathematical discourse. Their discourse on infinity and limit is consistent with the structural discourse of mathematical textbooks, and does not appear to draw on their previous everyday experience with discourse on infinity/1m,” and limithO”. K-speakers exhibited the tendency to use mathematical-objectified discourse on l infinity despite the fact that they did not have a good mastery of this discourse. One possible reason is the lack of alternatives. In other words, unlike E—speakers, K-speakers did not demonstrate a well developed non-mathematical discourse on infinity and thus kept using words from the mathematical discourse on infinity by employing phrases that appeared in the question. Another possible reason is they might have a stronger tendency than the E-speakers to remain in the discourse introduced by their interlocutor (interviewer). The results of item I (about creating a sentence) seem to confirm this. The question in item I framed the discourse as being about language or literature (note the request to create sentences) and the K-speakers’ answers were mame non-mathematical — much more so than those of E-speakers. The same may explain the results of II-a, which was about fingers and toes, where the routines of comparison chosen by K- speakers were often non-mathematical. There are other reasons to speculate on a connection between E-speakers’ mathematical and non-mathematical discourses on infinity and limit and a lack of connection in the K-speakers’. The change in wording for comparing two infinite sets 152 all‘Ol strongly influenced the way E-speakers implemented the comparison of sets, whereas it did not influence K-speakers’ choices. This difference reinforces the claim about a greater disconnection between the non-mathematical and mathematical discourse in the K-group. It seems that the K-speakers, rather than gradually proceeding from more processual non-mathematical discourse on infinite processes to a structural discourse on infinity, have been directly exposed in their mathematics classes to the structural formal mathematical version. E-speakers’ sensitivity to the wording of the question may be unu-—.__.._ 'l '0 evidence for a connection between colloquial and mathematical discourses on infinity and limit. In limit-finding tasks, the use of geometric representations was dominant in the B- group, compared to the use of algebraic representations in the K-group. The reasons for this difference are likely to be multifaceted. They may include discourse—related differences in the non-mathematical use of the word limit. Another may be differences in educational experiences prior to studying calculus. And, it is possible that the curricular emphasis on asymptotic behavior in the U.S. curriculum and the algebraic approach in Korea curriculum lead to a disposition to the use of a geometric approach that is more prominent in E-speakers. Another possible reason is the processual uses of E-speakers in non-mathematical discourse on limit and the structural uses of K-speakers in mathematical discourse. Additional research would be needed to understand this more fully. Students’ routines and endorsed narratives, as well as their visual mediators seem to be grounded in the characteristics of their word use (i.e., processual and structural uses of the words infinity and limit). For instance, E-speakers’ canonical interpretation of the 153 word infinity is consistent with processual uses of infinity. Their routines were employed on the basis of a syntactic mode of context due to a processual use of limit. In contrast, routines of K—speakers were used on the basis of objectified mode with a structural use of limit. K-speakers often reified limit-finding tasks with the idea of limit as a number. E-speakers’ responses were consistent with the canonical interpretation of infinity with processual explanations, and K-speakers’ interpretations were more consistent with l the canonical interpretation of limit. The interplay between non-mathematical and mathematical discourses on infinity can be helpful for E—speakers to develop their i canonical interpretations of infinity. However, the connection between non-mathematical and mathematical discourses on limit can be problematic because the non-mathematical and mathematical uses of the word limit are different and sometimes conflicting (i.e., The processual use was often characterized by unreachability). K-speakers seemed to differentiate mathematical discourse from non-mathematical discourse on both infinity and limit. This may help them develop the rigorous definitions and complicated structures that underlie the mathematical concept of limit without conflicts. However, the difference between non-mathematical and mathematical discourses on infinity may make it difficult for K-speakers to reify and conceive of infinity as a process, unlike E-speakers. A salient property in routines is that many respondents in both the E-group and the K-group used different routines for the different cases. This may be explained on the basis of the fact that learning (transfer) does not happen automatically, but takes time and practice. One may conjecture that students use different routines in different mathematical contexts. In other words, routines seem to be highly context—dependent. 154 The results of this study can also provide insights about the relationship between students’ self-concept in mathematics and their efforts in mathematics learning. Higher self-concept in mathematics may be related to more effort and better performance in some students, but may not in others. The E-speakers reported that they were more confident than the K-speakers about their capability of learning mathematics. This finding was consistent with previous studies (Chen & Stevenson, 1995; Stevenson, Chen, & Lee, 1993) that Chinese students were less confident than U.S. students about their mathematics learning. When students are working on mathematics homework, the Korean students’ lower confidence in mathematics may cause them to devote more time and effort to it, as other studies (e. g., Fuligni & Stevenson, 1995) have suggested. In addition, the result from the follow-up questionnaire suggests that for K-speakers learning was more central because they reported systematically devoting more thought and more time to it compared with E-speakers. In addition to the continuity in English and the discontinuity in Korean between the non-mathematical and mathematical discourses on infinity and limit, differences in the discourse opportunities between U.S. and Korean classrooms may be a possible reason which is likely to account for the differences in students’ mathematical discourse on these words between the E-group and K-group. Because the students in this study reported that their calculus instructors used lecture-style presentation for more than half of their lessons, one may conjecture that due to the processual nature of E-teachers’ mathematical talk about infinity and limit in their classrooms, E-students’ mathematical discourse on these words may be processual. In contrast, K—students’ mathematical discourse on the topics may be formally mathematical and structural perhaps because of K—teachers’ 155 mathematical and structural language in their classrooms. An investigation of differences in the nature of classroom discourse between the two groups may provide more thorough information about reasons for differences in their mathematical discourse on infinity and limit. The claim about the differences in the mathematics discourse on infinity and limit as caused by differences in the colloquial uses of these words, however, is supported with process-type causality argument rather than regularity-type causality. In other words, rather than trying to look for a statistical evidence for the co-appearance of the phenomena that are claimed to be in causal relation (similar uses of words infinity in limit in non-mathematical and mathematical discourses), I argued for the causal dependence by explaining how the non-mathematical discourse on infinity and limit leads to the mathematical discourse on these words. The results of this study confirmed the analytic argument: some English colloquial uses of infinity and limit reappeared in mathematical uses. In other words, E-speakers continued to use the words in the way they did so far. The absence of this type of use in Korean mathematical discourse on infinity and limit was also in accord with the claim about intra-discursive mechanisms: The unwanted types of use of the words infinity and limit which, in the English mathematical discourse, stemmed from the colloquial uses of these words did not appear in the K- speakers mathematical discourse. Considering all this, additional information on the classroom discourse in U.S. and Korea, although important, is of only secondary significance when it comes to substantiating the claim about the impact of colloquial discourses on their mathematical counterparts; The classroom discourse can strengthen or weaken this impact, but it is not its primary source. 156 Generalizabili The findings of this study may be generalizable to native-English speakers in the U.S. and native-Korean speakers in Korea who start to learn calculus in a university setting. However, generalizations from the present findings should be made with appropriate caution for several reasons. First, different geographical areas can be related to differences in students’ former education and curricular experience with infinity and limit as important factors in mathematical discourse. In addition, characteristics in mathematical discourse can be determined by various other factors such as socioeconomic status (SES) and university contexts. Since SES was not taken into account, and university differences were not considered in this study, the findings in this study did not reflect this potential influence of additional variables. Limitations of the Study There are several limitations of this study. First, the 132 U.S. and 126 Korean survey participants were not randomly selected out of the total population in the research sites. They were recruited from several calculus classes on a voluntary basis and thus area sample of convenience. Thus the findings from this work cannot be generalized beyond this group of students, although they provide important focused hypotheses for subsequent work. Second, there are some limitations in the survey and interview instruments. The chi-square results in the survey questions should be interpreted with caution due to the possible ambiguous nature of some questions to the students. For instance, the interpretation of “extra lessons” in question 193 could be interpreted 3 Question 19: During this school year, how often have you had extra lessons or tutoring in mathematics that is not part of your regular class? 157 differently, especially to the E-speakers. The meaning of “every day” in question 204 was also problematic because of the fact that the U.S. and Korean classes met three days and twice per week respectively. Third, follow-up interviews, with 20 % of the survey participants, were conducted in pairs. A possible limitation of this approach is that different pairings such as fiiendship pairings and acquaintance pairings may cause different levels of performance in mathematical discourse (e.g., Kumick & Kington, 2005). Variations in interviewees’ friendships were not controlled in this study, even though one or two pairs were randomly selected within each setting. It may be useful to include the relationship between different pairings and their mathematical performances in a further study. A fourth limitation is that the timing of data collection between in the U.S. and in Korea was different The Korean data of this study were collected in May 2007, the second half of the first semester for university freshmen in Korea, compared to the U.S. data in September or October 2007, the first half of the first semester for university freshmen in the United States. Because of the differences in timing, it could be expected that K-speakers had more opportunities to learn about limit in their calculus class. Finally, the K-speakers were exposed to English through the use of an English textbook in their calculus classrooms in college settings, even though the college lecturing was in Korean. However, the impact of the English calculus textbook may not be significant in terms of the effects of English on the K-speakers’ mathematics learning because mathematics in precollege settings in Korea is taught in Korean and its textbooks are in Korean. g 4 How often does your instructor give you homework in mathematics? 158 Further Questions One question that this study has raised concerns about is the generalizability of this study. Another question is about additional important variables which can affect mathematical discourse, such as socioeconomic status (SES) and social and organizational contexts. In the narrow sense of generalizability, the present study can be expanded by collecting data from other groups of students in other U.S. and Korean 1miversities. Additional comparisons of relationships between non-mathematical and mathematical discourses on infinity and limit could provide more comprehensive information about differences and similarities. In the broader sense of generalizability, the findings in the present study may not be generalizable to students in other East Asian countries, even though these East Asian languages share many common characteristics with Korean in terms of how mathematical words are represented and used. Further research could include students from different East Asian countries such as China, Japan, and Singapore, and could compare the results from the findings in those studies with those of the present study. In addition, groups of native speakers in East Asian countries could be compared with those of other native speakers in English-speaking countries. These comparisons could provide more thorough information about the phenomena caused by both continuity in English and discontinuity in East Asian languages between non-mathematical and mathematical discourses on infinity and limit. As for other important variables related to mathematical discourse, many further questions are still interesting. For example, given the belief that social and organizational contexts are relevant to mathematical discourse, one might ask, do students from different 159 university contexts differ in their non-mathematical and mathematical discourses? Examining how students’ SES is related to their mathematics performance, one might ask, do students from different SES levels differ in their non-mathematical and mathematical discourses? In addition, one might ask, is there a gender difference in non- mathematical and mathematical discourses? Mm Theoretical Conclusions For the last several decades, most previous research on how students learn mathematics has been based on cognitive psychological perspectives, called cognitive theories. These cognitive theories are implicitly grounded in absolutism, that is, the assumptions they hold about the nature of mathematics are context-independent. In cognitive theories influenced by the work of Piaget, mathematical learning has also been considered as a process of active cognitive acquisition. The acquisitionists who rely on the acquisition of mathematical concepts as mathematics learning have explained that the idea of cognitive processes is based on uniform and orderly forms of rule-following (Harre' & Gillett, 1995). Static constructs in mathematics education such as concept images and concept structures are useful descriptions in mathematical discourse. For a better understanding of how and why students think mathematical concepts, however, there needs to be a new emphasis on dynamic variables in learning mathematics. The findings of this study add two new perspectives to theoretical perspectives on learning mathematics. First, mathematical thinking is words-based thinking due to the sensitivity of word use in such ' thinking. We notice that different students could decipher different meanings and thus 160 engage in different thinking, even with respect to the same word, infinity. Second, mathematical thinking is also a continuously dynamic process, rather than a one-way directional internalization from others to the individual learner because of the contextual dependence of routines as interwoven processes with word use. To become more skillful and articulate in a certain mathematical discourse, students should continuously and dynamically interpret what others who are more discursively advanced in mathematics say, word by word, with routines due to dynamic processes of routines with word use. If students misunderstand words or misuse routines in these communicative activities, their learning could be inapplicable and even wrong in the mode of learning. Thus, it is warranted to move beyond the cognitive perspective and to examine continuous changes in the learning context through the study of word use and of routines. By not examining word use and routines in mathematical discourse, researchers may have a distorted view. To reveal situated learning difficulties, researchers need to investigate thinking in context rather than thought because of the sensitivity of word use and dynamic processes of routines based on word use. Thinking is an on-going process, whereas thought is the end product of thinking. Research methods that are sensitive to word use and dynamic processes of routines (by using visual mediators and endorsed narratives) need to be employed in order to explore questions about both how students know and why. One difficulty in the discursive approach to student learning is the requirement for a Common systematic and analytical framework. However, with a common framework of analyzing discourse that is well organized, discourse analysis is a theory-based research method including contextual sensitivity as well as addressing continuing processes in 161 learning mathematics. To improve mathematical learning in practice requires that research aids us not only in deepening our fundamental understanding, but also by indicating pragmatic processes for resolving student learning difi'rculties. Discourse analysis as a multi-lateral approach is a promising method to reveal the complex mechanisms of mathematical learning in contexts because it can be sensitive to word use as well as to the dynamic processes of routines as essential components in mathematical discourse. Practical Implications The results of the current study offer several implications for teaching and learning about infinity and limit. The findings indicate that how to use words may be the most fundamental and significant factor in determining the content students try to learn. Word use This study suggests that learning is highly words-dependent. Even though a teacher provides the same word several times on the same concept in class, students could grasp its unintended meaning because they decipher it from their own point of view. Often their interpretation might differ from what the teacher intended to explain. Thus, explicit dynamic dialogues between the teacher and students seem to be a promising pedagogical option to improve student learning difficulties. The most basic and critical perspective on teaching mathematics is to know the words which students use to communicate the meanings of mathematical concepts. Students’ learning difficulties may come from packed words which explain mathematical concepts and structures. Reifying the dense Words and their complex structures could assist students to more easily access 162 mathematical discourse fi'om their own point of view. It seems that mathematical learning starts with mathematical words and continues to develop through them. Using problem solving task for developing proficient word use and endorsed narratives Problem solving in calculus should continue to address how to use words, but it should also attempt to ascertain Students’ endorsed narratives. In order to assess students’ development in word use and endorsed narratives, instructors may need to use alternative assessment techniques such as oral exams and short-answer questions that ask students to discuss theirunderstanding of mathematical words. Problem solving itself may not improve Students’ word use and endorsed narratives without explicitly mentioning the relations between them. For instance, discussing why the limit of the sequence 1,1,1, is one might help students shift their word use of limit fiom rmreachability to reachability. With explicit clarifications of the relations between problem solving and word use (including endorsed narratives), each problem solving episode can be used to extend students’ word use and endorsed narratives from non- canonical to canonical interpretations. Making routines more precise The importance of routines in promoting mathematical learning is established in the mathematics education literature. In addition to the emphasis on routines in mathematical discourse, it isdesirable to make routines more precise. In other words, not only how to implement routines, but when to use those routines need to be explicitly expressed. The finding of this study — routines are highly context-dependent — supports such recommendations. In addition, differences between routines should be emphasized in terms of when and how to apply them for student understanding. Decompressing routines 163 to when and how to apply them step-by-step and differences between the routines would assist Students’ access to mathematical discourse. Thought and language are inseparable in the process of human developmental pathways (Vygotsky, 1986). Mathematical learning involves thinking with and through everyday language, generalizing everyday concepts associated with mathematical words, and abstracting those concepts with schooling. According to the results of the current study, non-mathematical discourse seems to have an impact on mathematical discourse due to certain clear differences between the mathematical discourses on infinity and limit of the E-speakers and those of the K-speakers. These differences can be ascribed to the fact that only in English do the mathematical words infinity and limit appear in non- mathematical discourse. Although some researchers (Cornu, 1992; Davis & Vinner, 1986) addressed the issue of everyday language conceptions on limit as a cognitive obstacle, they did not deal with how those conceptions were related to mathematical discourse on limit. Students’ non-mathematical discourse may have an impact not only on the students’ later use of the mathematical keywords, but also on other aspects of their mathematical discourse, such as endorsed narratives, routines, and visual mediators — a fact that should be kept in mind in both the research on advanced mathematical concepts and teaching advanced mathematics. I hope the practical and theoretical conclusions presented here will influence research in advanced mathematical thinking and improve Students’ learning of the notions of infinity and limit. 164 APPENDIX A THE PILOT STUDY QUESTIONNAIRE 165 The Pilot Stug Questionnaire 1. Create a sentence with the following word (term). Small Large 1 5 8 —2 Triangle Triangular Limited Limit . Diagonal lO. Infinite l 1. Infinity °P°SP~SAPP°N€ 11. Say the same thing without using the underlined word. 12. Some arrow points have triangular forms. 13. Eyeglasses are for people with limited eyesight. 14. There are infinitely too many lawyers. 15. He has infinite potential. 16. My love for you is infinite. 17. The limit of -1- is 0 as x approaches infinigy. ——' x 18. In box A, there are more matches than in box B. III. Which is a greater amount and how do you know? 19. A: Your fingers B: Your toes 20. A: Odd numbers B: Even numbers 21. A: Grains of sand in the world B: Size of the sky 22. A: Odd numbers B: Integers l 2 3 IV. —= 0.25, —= 0.25, -—= 0.25, 4 8 12 How many such equalities can you write? 166 V. What do you think will happen later in this table? How do you know? x Jx+25—5 x 1.0 0.099020 0.5 0.099505 0.1 0.099900 0.05 0.099950 0.01 0.099990 0.005 0.099995 0.001 0.099999 VI. What is the limit of the following when it goes to infinity? 1 23. — x x2 24. — l+x x2 25. (1+ x)2 VII. Read aloud x + 3x ___ %. Explain what it says. VIII. What is limit? What is infinity? 167 APPENDIX B OTHERS Overview of Education Systems in the United States and Korea Development of Korean Words Representative Analysis Examples (in terms of word use, endorsed narratives, visual mediators, and routines) 168 Qverview of Education Systems in the United States and Korea Korea has a centralized educational system Compulsory education in Korea begins with elementary education, when children are six years old. Elementary education has a duration of six years. Secondary education is divided into two stages: middle and high school education. Middle school lasts three years. High school education includes two separate programs: vocational and general education. Vocational education lasts three years and leads students to have a certificate for the labor market. General education also lasts three years and leads to the university. Postsecondary education in Korea includes both vocational and academic higher education. Vocational higher education usually lasts two years and results in an associate’s degree. Academic higher education includes the four university programs that lead to a bachelor’s, a master’s, a professional degree in medicine, and a doctoral degree respectively. In all universities, semester system is used during the academic year. Spring semester, which is the first semester of the academic year, goes from March to June, whereas fall semester period goes from September to December. Mathematics curricula in Korea are controlled by the Ministry of Education. The 7‘h School Curriculum is the latest published document (Korea Ministry of Education, 1997). According to the document, all students from grade I to 10 are required to take mathematics. From grade 11, students take mathematics elective courses. There are six elective courses: Mathematics 1, Mathematics 11, Applied Mathematics, Discrete mathematics, Calculus, and Probability and Statistics. Students who are going to study social science in the university are required to take only Mathematics 1. In contrast, students who want to study science in the university take both Mathematics 1 and 169 Mathematics 11 as requirements. They are also required to take one of the last four elective courses. The United States has a decentralized educational system. In other words, education is primarily a State and local responsibility (U.S. Department of Education, 2006). Primary education begins at age six in elementary schools and lasts for five or six years. Secondary education is divided into two levels. Lower secondary education has three or four years and is offered in grades six or seven to nine in middle school or junior high schools. Upper secondary education lasts three or four years and includes grades nine or L ten to twelve in high schools. Postsecondary education in the United States is offered in community colleges and includes vocational certification programs. Vocational higher education is typically about two years in length and results in an associate’s degree. Academic higher education includes four university programs that lead to the award of a bachelor’s degree, a master’s degree, a professional degree in fields such as medicine and law, and a Ph. D. Some universities in the U.S. are in a semester system, whereas other universities are in a quarter system. In a semester system, there are fall and spring semesters implemented as the first and second periods respectively. In a quarter system, there are four academic periods during the academic year. Mathematics curricula in the U.S. are each state’s responsibility. Thus, the standards and expectations to guide mathematics curriculum in Michigan have been developed by the Michigan Department of Education. The Michigan Department of Education’s Office of School Improvement led the developments of both the K-8 Mathematics Grade Level Content Expectations (GLCE) in 2004 and High School Content Expectations (HSCE) in 2006. The HSCE extends the GLCE as appropriate for grades 9-12. According to the 170 GLCE, all students from grade 1 to 8 are required to take mathematics. Based on Michigan’s HSCE, all high school students take four courses as requirements out of five choices. The three courses (Algebra I, Algebra II, and Geometry) are required and both Pre-calculus and Statistics and Probability are optional. The two different educational systems in the United States and Korea are summarized in Table I. Table 1: Overview of educational systems in the United States and Korea U. S. Korea System Decentralized Centralized Compulsory Elementary, middle school, Elementary, middle school, high education high school educations school educations Postsecondary Vocational and academic Vocational and academic higher Education higher educations educations For grades 1 _ 8, mathematics For grades 1 — 10, mathematics as a . requirement, For grades 11 and 12, as a requirement. For grades 9 . . . . . . . srx elective courses. Mathematics 1, Mathematics — 12, five elective courses. . . . Mathematics 11, Applied curriculum Algebra 1, Algebra II, . . . Mathematics, Discrete Mathematics, Geme‘ry’ P‘e'calculus" and Calculus and Probabili and Statistics and Probability Statistic; ‘y 171 ' 'm‘ _u'3q Development of Korean Words Korean has borrowed a huge number of Chinese characters. The Korean lexicon consists mainly of pure Korean words and Korean words built on Chinese characters: about 30 percent native Korean words and 65 percent Chinese character words (Sohn, 2006). Those borrowed words and Chinese characters have become integral parts of the Korean language. Ancient Koreans learned both the Chinese characters and language. However, they also explored ways of recording their native language with the Chinese characters. In the middle of the 15th century, Hunminjungeum (Hangtil - the Korean alphabet) was invented in order to bring literacy to the common people who were not intellectually elite and proficient in Literary Chinese (Lee & Ramsey, 2000). Until this time, there was no common way to read Chinese characters. From this time, many words in Korean were constructed as terms parallel to the words conveyed by Chinese characters and numerous words have also been created by Koreans represented with Chinese characters. Chinese characters are usually associated with the meanings of the words in Korean. Pronunciations and writing systems of borrowed Chinese-character words in Korean have evolved independently in Korea. Nowadays, use of Hangfil spellings has increased in newspapers and even scholarly books, and the use of Chinese characters is considerably limited (Sohn, 1999). To show meanings and etymologies of words more clearly, however, some professional writings, such as in law and in Korean history, continue to be written in Korean mixed with Chinese characters. As Korean language, culture, and society were influenced by Chinese language and culture in the past, they have currently been influenced by their American counterparts 172 since 1945. Most borrowed words after 1945 are words from English with American socio-cultural concepts. For instance, over ninety percent of some 20,000 borrowed words currently used. in Korean are from English, such as coffee, café, and hotel (Sohn, 2006) Most mathematical terminologies in Korean (e. g., infinite, infinity, limit, element, and set) were borrowed directly from the Chinese characters, but in school mathematics they are written in native Korean spellings without explaining the words with Chinese characters. For example, the word 91'— ?! in Korean terminology (without using the Chinese character of half: which means boundless or boundlessness) is written and read as mu-han in Korean pronunciations in a 7th grade mathematics textbook According to a Korean dictionary, there are two Korean mathematical words for infinity: 3?— Ei (mu-han) and 1:35;! EH (mu-han-dae). The first Chinese character (flit - mu) of the two mathematical words means none and the meaning of the second character (FE - han) is bound and the last character (ii-doe) means bigness. Thus, the word mu-han means “boundless or boundlessness,” whereas the meaning of the word mu-han-dae, used only in mathematics, is “boundless greatness.” A Korean word comprises one or more syllables. Most Korean syllables borrowed from Chinese characters are used colloquially and mathematically. Mathematical and colloquial uses of Korean words are determined by cultural and historical uses of the words, rather than their syllables or characters. The existence of sharing the same syllable or character between two words does not mean necessarily their colloquial uses or mathematical uses. Whether each syllable is used as part of either a colloquial word or a mathematical word is decided on the basis of whether the Korean word (including the 173 syllable) is either a colloquial term or a mathematical term. Korean colloquial words for infinity and limit are often used in everyday language rather than the mathematical words of infinity and limit. For instance, 9— 4‘- 8| (mu-su-hee, countlessly) or if 81 0| (hon-up- see, endlessly) are used for “infinitely” in colloquial Korean, rather than the mathematical word L?- 53 3| (mu-han-hee, infinitely). Instead of the mathematical word it 5i (gfik-han) for limit, the Korean colloquial words HI if (Jae-hon, limitation) and 23" 3‘11 (kyung-gae, boundary) are often employed. The Korean mathematical words for infinity and limit are summarized in Table 2. Table 2: Summary of the Korean mathematical words for infinity and limit . Korean English _ . , Words Pronuncratron Chinese characters Meaning . gr" ‘3’ mu-han m BE Boundless or boundlessness Infinity ‘ 5?- PJ CH mu-han-dae 315?: 7t Boundless greatness 2 it gfik.han @131? . Utmost boundary Limit A value to which a function :1 at F ' - - t m _ 3A guk han gab limit approaches 174 Representative Anaysis Examples In the first example of the pilot study, students were asked to define limit. The definitions of limit given by the students are presented in Table 3. Table 3: The summary of definitions of limit Students What is limit? A5 [1] Limit can go on and will stop at some point. A7 [2] The limit is the value of a number F > A10 [3] Limit is something that numbers can’t go past. They have to stop at a 3, a certarn pomt. z,- :::. [4] As not in mathematics, limit is the absolute ending of something like no 5 g more. In a mathematical sense, it would always be the ending of. . .like an i AU answer, but sense... numbers are infinite. You can get to the answer but J _. never reach the limit because there’s infinite numbers. . .kind of opposite in a way because there isn’t... there is no limit in infinity. K4 [5] Limit means like the maximum. W K7 [6] Limit is the furthest something to .go. .: like where it stops. . .like . g boundary you cannot go on. . .I think infinity IS the opposrte of the hunt. g Km [7] Limit is a certain number that you can’t reach but you get very close to. K [8] Limit is a special number. . .for instance if I say limit four, then there is U one, two, three, and four. Not over four. 1)‘ Word use Obiectification: There is a considerable difference with age in ways of defining the word limit. In the group of the younger participants in both ethnic groups, the word limit was used without explicitly relating it to numbers. In contrast, the older participants specified limit with numbers. Evidence of such a use (as an objectification) can be seen only in the utterances of the 10th graders and university students. In all such cases the entity was presented as a particular number or related to numbers (“something that numbers can’t go past” [3], “the answer” [4], “a certain number” [7], and “a special number” [8]; the status of the utterance [2] is unwarranted, in the present context). 2) Endorsed narratives The students’ definitions of limit revealed the following endorsed narrative. 175 Limit is an upper boundary; In this endorsement, limit is used to describe something that limits the process from above. Some of the students held this view, as evidenced by expressions such as: “limit can go on and will stop at some point” [1], “numbers can’t go past” [3], ‘you never reach the limit” [4, 7], “limit means like the maximum” [5], the “limit is the furthest something to go” [6], and “one, two, three, and four” [8]. . . 1 In the second example, students were asked to find the ill’lllt of — when x goes to x infinity. The summaries of students’ responses are presented in Table 4. Table 4: Summary of responses about the limit of l x 1 Students VI. (a) What is the limit of - when it goes to infinity? x A [9] This one is zero. . .because last time we looked at it. One (problem) equals 5 zero. . .x equals. . .infinity approaches... it’s like zero. A [10] I don’t know what the limit is... That’s gonna be one over infinity. g 7 When x goes on forever, one over forever. g- A [11] The limit is always one over infinity. . .infinity does have no g '0 limit. . .something keep going on and on. . .I am not sure what the limit is. [12] One (problem) would be zero because the bigger x gets. . .it just be AU smaller and smaller decimal. It’s a sense of going infinity, there is no ending which is gonna be very, very tiny. K4 [13] I don’t get what it means by when x goes to infinity... K [14] This would become zero. . .because the number one, you know one. . .this 7 will be close thirty. . .It won’t really be anything. g K [15] It will get close to zero. . .because x is two. . .point five. . .x. . .ten. . .it will '53 1° get to keep smaller and... g [16] Zero or one. . .I don’t remember exactly why. But I know it’s gonna be one or zero because I learned it. One over x goes to infinity. . .then I can say KU like. . .then I can think like one over infinity. . .if I divided one. . .one over one. . .but one over two is point five. . .that meaning is zero because infinity means too large number. 176 3) Visual mediators For the purpose of this analysis, I differentiated between three visual mediators from my observations. The words infinity and limit in the task can be syntactic mediators used for the sake of scanning mathematical contexts. The second type is concrete mediators which students used in order to perform operations related to the task of finding the limit. The third type of mediators is objectified, which are used to reify those operations with the purpose of finding limits. As explained below, these mediators can be employed in different ways within the process of calculating the same limit. The American 7th and 10th graders scanned the word limit in a defined way. To calculate the limit of l , the word x infinity was scanned as a process (“forever” [10], “keep going on and on” [11]) and the variable x in each function was replaced by infinity. In order to give an answer, they (A7 and A10) used algebraic expressions as mediators (“one over infinity” [11], [12]). This scanned process may be called syntactic mode, as it requires only knowing the words infinity and limit and algebraic expressions. In contrast, the word limit was used in different ways in the utterances of the American undergraduate and the Korean students (K7, K10, and KU). They (AU, K7, K10, and KU) manipulated concrete input values to calculate the limit of each function. Their first attempt at scanning the context of ‘x goes to infinity’ involved substituting a small number for x, performing the required operations (“you know one” [14], “two. . .point five” [15], “one over one” [16], AU showed “the bigger x gets” [12] as the process of substituting a small nmnber for x in the next problem) and then increasing the input values. In order to find the limit, they looked at the substituted values of each function and decided whether these values are increasing or decreasing to a number (approaching 177 a value). They turned spontaneously to concrete mode and then made a transition from concrete to objectified mode regarding the concept of limit as approaching a value. 4) Routines The routines of the American 7th and 10‘h graders were to substitute infinity for x by alluding to an operational use of infinity (“when x goes on forever” [10] and “something keep going on and on” [1 1]). They seemed to be using just one mediational mode .7 (syntactic) with little flexibility. This syntactic mode allows for very little interpretation of finding limits and no predictions. In contrast, the Koreans (K7, K10, and K0) and the American undergraduate substituted several increasing numbers for x (“the bigger x gets” [12], “the number one, you know one...this will be close thirty” [14], “x is two...point five...x...ten. . [15], and “if I divided one. . .but one over two. . .infinity means too large number” [16]) and 1 . . . . . . checked whether the values of — were increasmg or decreasrng to determine the limit. x In the case of -1— , they (K7, K10, KU, and Au) made a few transitions from one mediational x mode to another; from syntactic to concrete mode and then from concrete to obj ectified mode. Their flexibility from one mediational mode to another in the process of finding limits can be described as objectified discourse. This mediational flexibility provides more interpretations and predications regarding the concept of limit than only one mediational mode. 178 APPENDIX C QUESTIONNAIRE 179 QUESTIONNAIRE The purpose of this study is to investigate and compare how native-English and native- Korean speaking university students, who received their education respectively in the U.S. and in Korea, think about the concepts of infinity and limit. Participation is voluntary, and you are free to discontinue your participation at any time. If you agree to participate in the study, you can agree to participate in Part I, or Parts I and II. Part I: You will be asked several questions on this questionnaire. The questionnaire consists of two sections: Section I, Background; and Section II, Discourse. The questions on the questionnaire are dealing with your background regarding the mathematical concepts of infinity and limit, and questions about colloquial and mathematical discourses on these concepts. Based on your responses to these questions, you may be invited for an interview. Part 11: Some students will be asked to participate in a follow-up interview. The interviewer will ask pairs of students to think aloud about solving the same tasks presented in Part I. If you participate in the research study, you will be audio-taped, video-taped and transcribed in their entirely for further analysis. As compensation, each interviewee will receive 25 dollars. There are no risks associated with the survey and-interview. Any information obtained from this research will be kept strictly confidential. Only researchers will have access to these data. As soon as the investigators complete analysis, all video and audio data will be erased. You are free to ask any questions concerning the procedure. If you have any questions about this study, please contact the investigators (DJ Kim, 884-1481, kimdon14@msu.edu; Dr. Joan F errini-Munay, 432-1 4 90, jferrini@msu. edg; Dr. Anna Sfard, 353-0881, annasfar@math.msu.edu). If you have questions or concerns about your rights as a research participant, please feel free to contact Peter Vasilenko, Ph.D., Director of the Human Subject Protection Programs at Michigan State University: (51 7) 355-2180, fax: (51 7) 432-4503, irb@msu.edu, or regular mail: 202 Olds Hall, East Lansing, MI 48824. Your signature below indicates your voluntary agreement to participate in this study to increase our understanding of student conceptions of infinity and limit. Participant's Printed Name PID Participant's Signature Date 180 Section I: Background About You 1. Year: ’4 Freshman 413 Sophomore J Junior J Senior 2. Native Language: -J English 3 Korean J Other (Specify): 3. How often do you speak your native language at home? ’41 Always Ll Almost always J Sometimes J Never 4. About how many books are there in your home? (Do not count magazines, newspapers, or your school books.) '43 None or very few (0-10 books) J Enough to fill one shelf (1 1-25 books) '43 Enough to fill one bookcase (26-100 books) 11 Enough to fill two bookcases (101-200 books) '-J Enough to fill three or more bookcases (more than 200 books) Mathematics in School 5. Have you studied mathematics in any language other than your native language? L1 Yes —3 No If yes, specify the languages in which you learned mathematics: 6. Can you remember the first mathematics course in which you heard the word (mathematical) infinity? 43 Yes J No 181 7. If yes, specify in which grade(s) and in which course/class you heard the word (mathematical) infinity. Grade(s): Course: 8. Can you remember the first mathematics course in which you heard the word (mathematical) limit? 3 Yes J No 9. If yes, specify in which grade(s) and in which course/class you heard the word (mathematical) limit. Grade(s): Course: 10. Please specify from which high school textbook(s) series you studied among the examples below. If you used textbooks other than those in the examples, please check the box for Others. Core-Plus Math . Pr _ t Key Curriculum emanc s 016C Mathematics Press McDou a1 Littell (CPMP) Connections g 5) 6) Others The University of Chicago School M th mat' Pr ' t a fucsnifrp) 016° H0“ Prentice Hall 182 11. In high school, which course(s) in the series below did you take? Please check all the boxes that apply to you (under the textbook series you used). CPMP Math Connections Key curriculum McDougal Littell J Coursel 3 Math connections] J Algebra 3 Algebral "JESSIEEEWM"7.3"it'42ifi'c'éiiiééii3rié'é """ 365;.95'"""""3"6é3}£12t}§ """" .-::E?E€:ii-.-----.-if-.¥3f¥ii?&‘35€fi?3i?.-_-Ea??§ff‘fi------iésitiéf ....... J Course 4 UCSMP Holt Prentice Hall Others J Transition Math lJ Algebral L1 Pre-Algebra "Sign?"m""""'f'3"6é'c;;1}'飣§'"m"""Yieii'g'éfiii'i """"" "3"a.;'.;.;;.;;y"'"""'"'"fringing;""'"""Sagas; """"" "ZJ'XAIAQEJIigéBQW """""""""""""" B'Ai'g'éiirlé """"" 12. In high school, what is the most advanced mathematics course you took other than those in #11? Course: 13. Please check the box(es) next to topics which you have studied. When and where did this study occur? When Where [ELLLLFL‘LLL‘ Infinite processes Infinite decimal fractions Infinite sequence or series The sum of infinite geometric series Comparison of infinite sets Countable and uncountable sets Infinitely small or infinitesimal Other topic (Describe): ‘ 183 14. Please check the box(es) next to topics which you have studied. When and where did this study occur? When Where Limits to infinity The 8-6 (epsilon-delta) definition of limit Limit of a sequence or series Limit of a function numerically Limit of a function geometrically Limit and the definition of continuity Limit and the definition of the derivative L’LL'LL‘L'LQL. Other topic (Describe): 15. How much do you agree with these statements about learning mathematics? a lot .— a) I usually do well in mathematics. _.; I would like to take more mathematics in a school. “ Mathematics is more difficult for me than for many of my classmates. Sometimes, when I do not initially d) understand a new topic in mathematics, I _' know what I will never really understand it. e) Mathematics is not one of my strengths. 0 V L] f) I learn things quickly in mathematics. __: Check one box for each line Agree Agree Disagree Disagree i—V ‘. ...-i t t .._J .— ._J l I ll [-1 16. How much do you agree with these statements about mathematics? a little a little a lot [3 [‘l w [3 Agree Agree Disagree Disagree a lot a) I think learning mathematics will help me n in my daily life. T b) I need mathematics to learn other school subjects. ”’ c) I need to do well in mathematics to get into ,—. the university of my choice. T d) I would like a job that involved using 1 mathematics. T e) I need to do well in mathematics to get the _: job I want. _ 184 [J .fi a little a little a lot I: 17. How often do you do these things in your mathematics lessons? Every or About Some Never almost half the lessons every lessons lesson a) We work together in small groups. I! D I L b) We relate what we are learning in n D _. L mathematics to our daily lives. 7‘ ' 7 c) We explain our answers. 1 D L”; L We decide on our own procedures for .—. _ d) . _ D _ L solvmg complex problems. e) We review our homework. I B I [I t) We listen to the teacher give a lecture- +7 E .. D style presentation. 7 ’ " g) We work problems on our own. I E I L h) We use calculators. : D I L Things You Do Outside of School 18. On a normal school day, how much time do you spend before or after school doing each of these things? No time Less than 1-2 More than 1 hour hours 2 hours a) I watch television and videos. I: E : I b) I play computer games. D [3 L _ c) I play or talk with fiiends. C: D Z : d) I do jobs at home. [I L 2 i: e) I work at a paid job. I: L: I I f) I play sports. L E :3 ”Z g) I read a book for enjoyment. L C : 2 h) I use the intemet. E E I _ i) I do homework. I: E _ : 19. During this school year, how often have you had extra lessons or tutoring in mathematics that is not part of your regular class? J Every or almost every day '—J Once or twice a week 41 Sometimes '—3 Never or almost never 185 20. How often does your instructor give you homework in mathematics? J Every day J 3 or 4 times a week J l or 2 times a week “—1 Less than once a week 4—1 Never 21. When your instructor gives you mathematics homework, about how many minutes are you usually given? ll Fewer than 15 minutes 3 15-30 minutes 11 31-60 minutes —3 61-90 minutes J More than 90 minutes 186 Section II: Discourse 1. Create a sentence with the following word (term). 1. Limited: 2. Limit: 3. Infinite: 4. Infinity: 11. Of which are there more? Please check one of the boxes. How do you know? 5. :1 Of your fingers or [3 Of your toes Because: 6. 2 Of odd numbers or E Of even numbers Because: 7. 2 Of odd numbers or [3 Of integers Because: 111. Which of the two sets A and B is bigger? How do you know? A = { l, 2, 3, 4, 5, 6, 7, 8, } B = { 2, 4, 6, 8, 10, 12, 14, 16, } Answer: Because: 187 IV. A student claims that each of the two sets A and B is infinite, but A is larger than B. What can this mean? Response: V. What do you think will happen later in the columns of this table? x Jx+25—5 x 1 .0 0.099020 0.5 0.099505 0. 1 0.099900 0.05 0.099950 0.01 0.099990 0.005 0.099995 0.001 0.099999 Answer: Because:__v__w___ ..., 7 7, .7 .7 .. _. .-., 188 VI. What happens to the curve as it approaches 0 from left or from right? 3.1 x Answer: Because: What will happen to the curve in #9 and in # 10 when it goes to positive infinity? x2. 1+x 9. Answer: Because: 189 10 ' (1+x)2 t T I n '1 L. 17 Answer: Because: VII. Examine the sequence of the square, the regular pentagon, hexagon (6 sides), heptagon (7 sides), ..., which is inscribed in the circle. 6 What happens if you continue increasing the number of sides of a regular polygon inscribed in a circle? Explain your reasoning. Answer: Because: 190 VIII. A student claims that a sequence a1, a2, a3, goes to infinity. What does this mean? Response: » A student claims that the number P is the limit of a sequence a1, a2, a3, What does this mean? Response: mhn'~--. -..,...__._. .. ..L, --H L .. Vifl-.,.. _ - _____-. _ . _... -....- _. ._... .... .. .. .__-. _.... ..._ .-..L - .. __ .. ”77...... .. .__.._........ .-.-.. ..., . . . ‘_.. - fl .. 7+ . 191 ZEAIEHI II $53- }.AIE-IIIIIOIIH OIIBIJIII :Q% 011 2%‘6IE§ B—TJEIOI’é'Bd‘éILICI. 0| XIIIIE c3H9! LIEQE LI-‘r-OIII o'fiLICI 731311111 £45, UHo; $31M "JIE, ‘é‘s‘ai. EEAIIIiIIIOII 0': E-EIEO Q-éiill 3319.1 45231751 DWI-3&0“ CHEI i‘éfl‘zfl HHgfll OI DWI-3&0“ CHE-fl 926151 DEID ““1213 ‘é’s‘aI-S— CHE-II. QAELICI. 0| 59:21-20“ CHEI §B§§ 3I$2§91E17=401| 5104521450 ELICI'. $2111» $5: gee {stage $91 11H OIEIwOII swag: spamme— at car: | 'IJIII AE—él—E-IIOIIO :DEI-e 391:: some. IE—TIOII anIIaIJIIEICII uses/so %6H c. eIL LICI ease anIIxIOIIJII: 25% ago H] II“ >53 >3! IE .19 IIII'LI o HIC|2315=§IEI E'ZIEIDI IlggfigLIU. QEII 351021 951.20" 4.3348 $1§Q§3C «ELIE 0| clI-POII/x-I gOIII— E7325- UH-‘f— 213481311 UIPE'BI 230.5% $41,151. I 04:11} 0101 0| EIIOIEI§ EBMQLICI. Ei-T‘IIEOI E’ig DIiIII DIX} 9% get 9—4 HICIQ Iifi'f: éiflia iCéILICI. E-TIEE DIE1 g EE IIO‘EJII “52’4“- ?AELICI. 01 04730“ [NEH/(I jéfiE—OIM 0' 29': [LI-$91 E ? II— a OII JII 9": §§¢ 9).; LI CI (3:! E 93 (02)379-9328(Korea), (517)884- 1481 (USA), kimdon14@msu.edu; Dr. Joan Ferrini-Mundy, (51 7)432-1490 (USA), (terrinflalmsuedu; Dr. Anna Sfard, 353- 0881 (USA), annasfar@)nath.msu.edu). E 7r1 3101 Iii/<1 3481011 CH6H éI-E-Ol LI g 8151: $EOI 9.128 @HIEII Ill-3 AI‘EIOIIJII 9“: @181 $1 AI 2 (Peter Vasilenko Ph.D., Director of the Human Subject Protection Programs at Michigan State University: (51 7) 355-2180 (USA), fax: (51 7) 432- 4503, irb@msu.edu, or regular mail: 202 Olds Hall, East Lansing, MI 48824). OIEHPJ 2.1/£91 A4238 513311311 3530“ EH?! iI/ggo Olc‘IH: EDIAIBIDH’ISH OI Bil—710" ’SOIISIRIICIE Eil‘JQI 11% In l'9 0H1 [Q mlfll I: E E [If >2 [190 C: D111 @0111 OI-E- EIE 730411 M93 ‘é‘RI new LII-Id: UH§ IIILIOII HIGH/cl z2L: LI Ieaa "_I zines.“ _—, 3:252." .1 452545“ , 22m .. _I am A team ..I cream (XIAIISI MIR): (2:. OIDIII mas EDNA-l 6.12%; EILIDI? _’j “QM- J 3194 we .I we _, an an egg . CIIOI anIL... we seem £1011IELIDIHXIII-Z-OILI’JE-é-EEEEIr—Ilflég HINDI/€113.) 3 81311.1 DH?- 751% (0-10 i4) 37c? 5JEI° iHO’éIEUl-Zfi 24) 3’3 §I3H§ IHo’éIE (263-100 3) 37¢“! $3H§ iHo’éiE (101200 E) 3475* kIIDHLI :1 DIN-9 111% XAE (200 24 Ol’c‘I) LL L I.” 31.314“— §IOII EIIfll/vl 5. EEOI OIEIOII CI—E— @OIE #iI-B-‘f-g— 6H EEOI OIELIDI? J 011 _’I OILIQ DI‘Ot “mlncfl l__l 4523]; UHJ‘EIE EOIE§ fi’JAIQ: u,— "$222+" OIBI-E EDIE gate a #55112; DIOI ‘ILIDI? —I Oil J OILIQ 193 PJQI "DIVE. QEIOIEIE EIOIS HggflE-ZI {ii-.3} 312% IIkl18| 3591109.. “ELEVOIFLIE EIOIE $9.191 5d #54213:- Jlfi'ILIDI? 2 Oil L- OILIsO. BIB? “are gamma 9mg fag—I ERIE—1| “Ln use nnIeI acme. Ova a: .CI% OIEHE’J Ollfllggollkl OIIEI-E-OI Mgiflrfl 2%5Ifl Elli/rig EAISIQI A12. DJ‘AI OIIXII-g-EI DIE Elli/OI; AigflQE. [HERE/H Q0“ EMSIGIAIR. 1) 2) I 3) fl 194 LIDI? II’JOI AIgflE‘I EDI/H .3 9o 5431M. OIEHEI OIBHOII IIL‘JOIIHI 3' 11.2% :5 Ir AL 5. EDI/d A $1— ILI .6; CH ELEM-I a ...2 m. J 4—5.‘ IO-DI, LI I? ._o_. AT 3451'?” 8|» _. --------.--------iI-u-Q-uoccohu-c J 4521‘ IO-DI, LI Man “..I a AT I ..Ia AT a: E E ----------1------ gLJ #21" lO-DI, LI at: AT" New '..J Q AT afi AT 5 a m E Ir ----------C--------J-..-.- TI ¢§I IO-DI, LI A- eTs A1 a .1 I? __o_- AT ..-----n---------o----------q------oconoocuooo------n-n-q -......o.......—..--..--... as AT O--------------------------u--------------------—------.—------—--------------—----4 -—--w-c-o------------------ E a m E LIE— IIIBIA‘I II 5IAI AA 9 .55 a on m mo .8 ...-....-1 TI 455-54 IO-DI, LI a m AT 20 Ma Q AT as AT TI [ll-EDI 75.-E- aT AT Be Na 3 #53 IO-DI, LI aT AT ------------------------------ >---------------------QCO-oq 4 Tan II I ..2 AT 30 Ma -...-........-.-..---.-.-...-...p....---.----.-..------.-.—...- i-------------- J ink—{51‘ lO-DI, LI .--------------------—----------P------------------------------‘II-‘O----------------------q A? AT JTéIII '-----C-------------------------L------------------------------ b----U-------—------------od E a m E Ea m ...2 12.-3541101191E313I CE'IEI 2% LIDI? 2. 1:1 BIKII OILIA-I UHf’i 8IHIQ. 180481-301 £$5J 11135":- EN OILIkI @111 N A._ ....e a 2. 2. AT 3 L: E ma AT ..9 E. ....g 9 AT 2 mm M ...3 2. m uu ml: Ea a: E. ....e 2. a: x: L: .3 an L: mu AT we HIE (fl’él/RIQI3 A a AT .5. E C nnnnnnnn 195 14.043I-i-0l {5131235.} HIS-2";- EM Ikllfl. QJXII OICIH UHflELIDI? OII 9.2m 04cm 2 22 22:4 :4 2-5 (epsilon-delta)9_| 22 291 .4 22m 2294 222 .4 £44229 “24:94 22:24 .4 3422294 “294 222 a 22474 93294 294 4 222234 04294 294 ".2 LE- HI2<22A49> 15 2.222 WEE-$2310" 12:2 43294 22201IEH6H 244922 294 EIéILIDI? 2 2014424 22142 4345444452 204 22 22 204 294 294 29 2* 294 22 a) LE 22292 222 2241 r: a : : b) LE 22014424 #2222 4:4 2:423. E : : : ) 2 22 2942-223 2201 LI 43412 E .4; ,_3 9 C O'IECI’ ...- =_4 _: 3422 2.2294 41422 3442—2 2204 d) 0464422 912%. LE um 22 043422 4: 3 : : 91-2 310121 EH3. e) #22 U9 3 22 SILIDI OILlCI. a : :4 : f) LIE 455-54; gal UH‘E‘ . [I : :3 : 16. 42222044 22:24 54294 2220140164 20242 294 542L4m? 204 25.2 32.2 204 294 294 291 2'2 294 2'2 LE 2.222 5412222 2222044 _ 4 a) 2204 202 22424:} I; L b — LE CE- 221214422 UHTDI 9424 2204 .. H b) Ié'Q'o'IEI L I; E - L443} 222 2014 2019434 9454 LE _ w _ c) 222 22 2234 944:4. ‘ I: I: — (1) LE 2.222 042642 222 20422. 2 2 : LE Laura-5422222749424 2.2222 E E e) 22 29234 914:}. ' — 196 F‘ ~_‘- «24.-4+1 1722220434 3294 2:22 233 I42 22le? (22) 222 222 225 22 2 22 22 22 4220434 a) 222 2223204w 21442223. 3 3 3 3 b) ZEiJ—Emw 4444222 22222 3 : 2 3 c) 29494 3422 2223. 3 3 3 3 d) 2223 23:2 6 28I3|%8H_ 3 2 : 3 Tam/394 04423422 2223. e) 2341:4394 2x42 2223. 3 3 3 3 t) 294 2294 2.222 223. 3 3 3 3 g). 222 23222 22232 23. 3 : 3 3 h) 2342 3113342 A4223. 3 3 : 3 234294 3150" HIGH/21 18.¥§i 23201422043043042014 32 22044 232294 A422 23144? a) TV LI 4143522 23. 3 3 : 3 b) 223 3442-2 233. 3 3 3 : 0) 229+ 2343 040+)! 23. 3 3 3 3 d) 2014/24 22 2.33. 3 3 3 3 e) 22 2E 22 233. 3 3 3 3 f) E%% EH}. B [j :3 :. g) 23434 24644 2+2 223 3 3 3 3 h) 2322 M223. 3 3 3 3 i) 2342 2+3. 3 3 3 3 19.042 2222 222220143494 22043322 233 I42 222L434? 3 0442 22 3494 0442 4+ 222014 23 22 44 3422 4+ 334 9.92 3494 22 2M 22 197 E 20. 233 I}??— ¢§’5‘4H|3} $01ELID}? 9 U W. ..9 3 ”JOILJ 43* EEOILJ $91 Oil Oil Oil ma 5. 5. x_. i W ma me me we J J J J 1. OIE :::-MESH)?” 2 2 2 1 2 9 ID: a: a: at a: 5 1 .J O a 5 J J 31-60 13 61-90 Ao '—J 90%-0| 198 1 51.1598 2. HIE-1* II. OLEEOI El E’JEUD}? EUlIl-S- EAl‘o‘iélAlSE. 0193" 2492mm? 5. F] Hg 3.53}? EE [‘1 L19] 331121 III. A 2} B 1732-;- §01|k| Mtg-0| El 9231.11»? Gig)" 24:12:31,131? A: { 1, 2, 3, 4, 5, 6, 7, 8, ..} B = { 2, 4, 6, 8, 10, 12, 14, 16, } 199 IV. E 8:19} “1'; Eat A9} B ERIC! $§10|IIEI AE BEG 30"331 :::-Qi‘ifiLICL DIES $935 PJUI ’45 ElfiL—IDI? V. 0| 51101-3 2! QEOIIM LIED" 0191 $01 $QQ1‘OIEID éL‘ZfEIL—ID}? x Jx+25—5 x 1 .0 0.099020 0.5 0.099505 0.1 0.099900 0.05 0.099950 0.01 0.099990 0.005 0.099995 0.001 0.099999 200 VI.x 3} EQOIIML} QEQOIIH 02E DIDHIIQIIH, 0'32! 2&8 0193" SLIM? 8,}. x Ova—Dri 8 0193“ ELIE}? flllfl x 3} QJQQQCHE EDIE: fill, 52’ 92} 100" 2).-E 25 x2 1+x 201 10. x, (1+x) a: Olvgri __ _____--,__ _,__-_ ,_-__ _____ VII. £19.: EDIE—2| 8 910" LHEAIi' EAR-kg, Q2233, asag, EQZIEn-u Egg] :8 @216" 291MB. 6 /"‘\ /‘\ . \J .. . . 0| EQEOIIH Lfla UQQQJ HQ #3} Ila“: 311!!! 0193“ SLIM? 0131-59-1 8%? Qgfifl EQAIQ. 9.3 Olgi ,, 202 VIII. E! 8:13} “#g a1, a2, a3, ...°] $§12§ PJCF'I’. $§ELICL 0318 9%;- QUIE‘UD}? E} 8:19} “4‘- E 45% al, a2,a3, ...9J EEOIU' E'JI’. $§§Lfll Olié’ $fi§ QDIQUD}? IX. $0113 901% Olgfiflld 2* E733 PJEMIQ. 11.3739: 12.2% _ __ “ -7 f _-__ ___ - 13.??29 »_ w ___* _-- “A ‘_ _ _ _ ,. 14.9—23.1 203 REFERENCES 204 REFERENCES Aczel, A. D. (2000). The mystery of the aleph: Mathematics, the kabbalah, and the search for infinity. New York, NY: Washington Square Press. Allen, G. D. (1999). The History of Infinity: What is it? Where did it come fi'om? How do we use it? Who are the inventors? Retrieved May 10, 2004, from http://www.math.tamu.edu/~don.allen/masters/infinity/infinitypdf. Anderson, A., Anderson, J ., & Shapiro, J. (2004). Mathematical discourse in shared storybook reading. Journal for Research in Mathematics Education. 35, 5-33. Artigue, M. (1992). Analysis. In D. Tall (Ed.), Advanced mathematical thinking (pp. 167- 198). Dordrecht, The Netherlands: Kluwer Academic. Barwell, K (2003). Patterns of attention in the interaction of a primary school mathematics student with English as an additional language. Educational Studies in Mathematics, 53, 35-59. Barwell, R. (2005). Language in the mathematics classroom. Language and Education, 19, 96 -101. Ben-Yehuda, M., Lavy, 1., Linchevski, L., & Sfard, A. (2005). Doing wrong with words or what ars students’ access to arithmetical discourses. Journal for Research in Mathematics Education, 36, 176-247. Berlinghofi', W. P., Sloyer, C., & Hayden, R. W. (2000). Math Connections. A secondary Mathematics Core Curriculum (Book La.) Armonk, NY: IT’S ABOUT TIME. Bintz, W. P., & Moore, S. D. (2002). Using literature to support mathematical thinking in middle school. Middle School Journal, 34, 25-32. Borasi, R (1985). Errors in the enumeration of infinite sets. Focus on Learning Problems in Mathematics, 7, 77-89. Boyer, C. (1949). The history of the calculus and its conceptual development. New York, NY: Dover. Brownell, W. A. (1945). When is arithmetic meaningfitl? Journal of Educational Research, 38, 481-498. Chen, C., & Stevenson, H. W. (1995). Motivation and mathematics achievement: A comparative study of Asian American, Caucasian-American, and East Asian high school students. Child Development, 66(4), 1215-1234. Cobb, P. (1994). Where is the mind? Constructivist and socio-cultural approaches on mathematical development. Educational Researcher, 23, 13-20. 205 Cobb, P. (1995). Cultural tools and mathematical learning: A case study. Journal for Research in Mathematics Education, 26, 362-385. Corbin, J., & Strauss, A. (1990). Grounded theory research: Procedures, canons, and evaluative criteria. Qualitative Sociology, 13, 3-21. Cornu, B. (1992). Limits. In D. Tall (Ed.), Advanced mathematical thinking (pp. 153- 166). Dordrecht, The Netherlands: Kluwer Academic. Cotter, J. A. (2000). Using language and visualization to teach place value. Teaching Children Mathematics, 7, 108-114. Cottrill, J ., Dubinsky, E., Nichols, D., Schwingendorf, K., Thomas, K., & Vidakovic, D. (1996). Understanding the limit concept: Beginning with a coordinated process scheme. Journal of Mathematical Behavior, 15, 167—192. Coxford, A. F., Fey, J. T., Hirsch, C. R., Schoen, H. L., Burrill, G., Hart, E. W., Watkins, A. E. with Messenger, M. J., & Ritsema, B. (1997). Contemporary mathematics in context: A unified approach (Course 1, Course 2, Course 3 and Course 4). Columbus, OH: Glencoe/McGraw-Hill. Davis, R., & Vinner, S. (1986). The notion of limit: Some seemingly unavoidable misconception stages. Journal of Mathematical Behavior, 5, 281-303. Edwards, C. H. (1979). The historical development of the calculus. New York, NY: Springer-Verlag. Edwards, D. (1997). Discourse and cognition. Thousand Oaks, CA: Sage Publications. Ernest, P. (1994). The philosophy of mathematics and the didactics of mathematics. In R. Biehler, R. W. Scholz, R. StraBer, and B. Winkelmann (Eds), Didactics of mathematics as a scientific discipline. Dordrecht, Boston: Kluwer Academic Publishers Fischbein, E. (2001). Tacit models and infinity. Educational Studies in Mathematics, 48, 309-329. Fischbein, E., Tirosh, D., & Hess, P. (1979). The intuition of infinity. Educational Studies in Mathematics, 10, 3-40. Fischbein, E., Tirosh, D., & Melamed, U. (1981). Is it possible to measure the intuitive acceptance of a mathematical statement? Educational Studies in Mathematics, 12, 491-512. Fuson, K. C., & Kwon, Y. (1992). Learning addition and subtraction: Effects of number word and other cultural tools. In J. Bideau, C. Meljac, &J. P. Fisher (Eds), Pathways to number (pp. 351-374). Hillsdale, NJ: Erlbaum. 206 Gadakiri. (1992). The process of problem solving and question analysis. Seoul, Korea: Kyung-Mun company. Gray, E., Pinto, M., Pitta, D., & Tall, D. (1999). Knowledge construction and diverging thinking in elementary & advanced mathematics. Educational Studies in Mathematics, 38, 111-133. Gutierrez, R (2002). Beyond essentialism: The complexity of language in teaching mathematics to Latina/o students. American Educational Research Journal, 39, 1047- 1088. Hairer, E., & Wanner, G. (1995). Analysis by its history. New York, NY: Springer-Verlag. Han, Y., & Ginsburg, H. P. (2001). Chinese and English mathematics language: The relationship between linguistic clarity and mathematics performance. Mathematical Thinking and Learning, 3(2-3 ), 201-220. Hersh, R. (1997). What is mathematics, really? New York, NY: Oxford University Press. Jahnke, H. N. (2001). Cantor’s cardinal and ordinal infinites: An epistemological and didactic view. Educational Studies in mathematics, 48, 175-197. Kim, D. (2006). Students ’ colloquial and mathematical discourses an infinity and limit: The case of American and Korean students. Unpublished doctoral practicum, Michigan State University, East Lansing. Kim, D., Sfard, A., & Fenini-Mundy, J. (2005a). Students’ colloquial and mathematical discourses on infinity. In Chick, H. L., & Vincent, J. L. (Eds), Proceedings of the 29th Conference of the International Group for the Psychology of Mathematics Education (Vol. 3, pp. 201—208). Melbourne, Australia: PME. Kim, D., Sfard, A., & Ferrini-Mundy, J. (2005b). Students’ colloquial and mathematical discourses on limit. In G.M. Lloyd, M.R Wilson, J .L.M. Wilkins, & S.L. Behm(Eds.), Proceedings of the 27th Annual Meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education [CD-ROM]. Eugene, OR: All Academic. Kleiner, 1. (2001 ). History of the infinitely small and the infinitely large in calculus. Educational Studies in Mathematics, 48, 137-174. Korea Ministry of Education (1997). The school curriculum of the Republic of Korea. Retrieved December 8, 2006, from http://www.moe.go.kr/search Lakoff, G., & Nunez, R. E. (2000). Where mathematics comes fi'om: How the embodied - mind brings mathematics into being. New York, NY: Basic Books. Lave, J. (1988). Life after school. Cognition in practice. (pp. 45-75). Cambridge: Cambridge University Press. 207 Lee, I., & Ramsey, S. R. (2000). The Korean language. Albany, NY: State University of New York Press. Leung, C. (2005). Mathematical vocabulary: Fixers of knowledge or points of exploration? Language and Education, 19, 126-134. Li, C., & Nuttall, R. (2001). Writing Chinese and mathematics achievement: A study with Chinese-American undergraduates. Mathematics Education Research Journal, 13(1), 15-27. Mamona—Downs, J. (2001). Letting the intuitive bear on the formal; A didactical approach for the understanding of the limit of a sequence. Educational Studies in Mathematics, 48, 259-288. Maor, E. (1987). T o infinity and beyond: A cultural history of the infinite. Princeton: Princeton University Press. Miura, I. T., Okamoto, Y., Kim, C. C., Chang, C. M., Steere, M., Fayol, M. (1994). Comparisons of children’s cognitive representation of number: China, France, Japan, Korea, Sweden, and the United States. International Journal of Behavioral Development, 1 7, 401-411. Monaghan, J. (1991). Problems with the language of limits. For the Learning of Mathematics, 11, 20-24. Monaghan, J. (2001). Young peoples’ ideas of infinity. Educational Studies in Mathematics, 48, 239-257. ' Mooney, C. G. (2000). Theories of childhood: An introduction to Dewey, Montessori, Erickson, Piaget, &. Vygotsky. St. Paul, MN: Redleaf Press. Moore, A.W. (1990). The Infinite. London: Routledge. Moschikovich, J. (1996). Learning in two languages. In L. Puig & A. Gutierezz (Eds), Proceedings of the 20th Conference of the International Group for the Psychology of Mathematics Education (Vol. 4, pp. 27-34). Valencia: Universitat De Valencia. Moss, J., & Case, R. (1999). Developing children’s understanding of the rational numbers: A new model and experimental curriculum. Journal for Research in Mathematics Education, 30, 122-147. National Research Council. (2001). Adding it up: Helping children learn mathematics. J. Kilpatn'ck, J. Swafford, and B. Findell (Eds). Mathematics Learning Study Committee, Center for Education, Division of Behavior and social Science and Education. Washington, DC: National Academy Press. Nunes, T., Schliemann, A., & Carraher, D. (1993). Street mathematics and school mathematics(pp. 1-27). Cambridge, MA: Cambridge University Press. 208 Pallant, J. (2005). SPSS survival manual: A step by step guide to data analysis using SPSS version 12 (2“d ed.). Buckingham: Open University Press. Pimm, D. (1984). Who is we? Mathematics Teaching, 107, 39-42. Pirie, S., & Kieren, T. E. (1992). Watching Sandy’s understanding grow. Journal of Mathematical Behavior, 11, 243-257. Przenioslo, M. (2004). Image of the limit of function formed in the course of mathematical studies at the university. Educational Studies in Mathematics, 55, 103- 132. Raiker, A. (2002). Spoken language and mathematics. Cambridge Journal of Education, 32, 45-60. Rogoff, B. (1990). Apprenticeship in thinking: Cognitive development in social context. New York: Oxford University Press. Rotman, B. (1993). Ad Infinitum...the ghost in T uring's machine: Taking God out of mathematics and putting the body back in. Stanford, CA: Stanford University Press. Rubenstein, R N., & Schwartz, R. K. (2000). Word histories: Melding mathematics and meanings. Mathematics Teacher, 93, 664-669. Rucker, R (1995). Infinity, Infinity and the mind: The science and philosophy of the infinite (pp. l-52). Princeton, NJ: Princeton University Press. Schwarzenberger, R., & Tall, D. (1978). Conflict in the learning of real numbers and limits. Mathematics Teaching, 82, 4-4-49. Setati, M. (2002). Researching mathematics education and language in multilingual South Africa. Mathematics Educator, 12, 6-20. Sfard, A. (1998). On two metaphors for learning and the dangers of choosing just one. Educational Researcher, 27, 4-13. Sfard, A. (2000). Steering (dis)course between metaphors and rigor: Using focal analysis to investigate an emergence of mathematical objects. Journal for Research in Mathematics Education. 31, 296-327. Sfard, A. (2001a). Learning mathematics as developing a discourse. In R. Speiser, C. Maher, & C. Walter (Eds), Proceedings of 21st Conference of PME—NA (pp. 23-44). Columbus, Ohio: Clearing House for Science, Mathematics, and Environmental Education Sfard, A. (2001b). There is more to discourse than meets the ears: Learning from mathematical communication things that we have not known before. Educational Studies in Mathematics, 46, 13-57. 209 Sfard, A. (2006). Participationist discourse on mathematical learning. In J. MaaB & W. Schloglmann (Eds), New mathematics education research and practice (pp. 153-170). Rotterdam, The Netherlands: Sense Publisher. Sfard A., & Lavie, I. (2005). Why cannot children see as the same what grown-ups cannot see as different? — Early numerical thinking revisited. Cognition and Instruction, 23 (2), 237-309. Sierpinska, A. (1987). Humanities students and epistemological obstacles related to limits. Educational Studies in Mathematics, 18, 371-397. Sierpinska, A. (1998). Three epistemologies, three views of classroom communication: Constructivism, sociocultural approaches, interactionism. In H. Steinbring, M.G. Bartolini Bussi & A Sierpinska (Eds), Language and Communication in the Mathematics Classroom (pp. 30—62). Reston, VA: NCTM. Skemp, R. R. (1987). The psychology of leaning mathematics (Expanded American ed.). Hillsdale, NJ: Lawrence Erlbaum. Smith 111, J. P. (2002). The Development of Students’ Knowledge of Fractions and Ratios. In B. Litwiller (Ed), Making Sense of Fractions, Ratios, and Proportions: 2002 Yearbook (pp. 3-17). Reston, VA: National Council of Teachers of Mathematics. Sohn, H. M. (1999). The Korean language. Cambridge, UK: Cambridge University Press. Sohn, H. .M. (2006). Korean in contact with Chinese. In H. M. Sohn (Ed), Korean language in culture and society. Honolulu, HI: University of Hawai'i Press. SPSS for Windows, Rel. 16.0.1. 2007. Chicago: SPSS Inc. Stevenson, H. W., Chen, C., & Lee, S. (1993). Motivation and achievement of gifted children in East Asia and the United States. Journal for the Education of the Gified, 16(3), 223-250. Tall, D. (1980). The notion of infinite measuring number and its relevance in the intuition of infinity. Educational Studies in Mathematics, 11, 271-284. Tall, D. (1992). The transition to advanced mathematical thinking: Functions, limits, infinity and proof. In D.A. Grouws (Ed.), Handbook of research on mathematics teaching and learning (pp. 495-5 1 1). New York: Macmillan. Tall, D. (2000). Cognitive development in advanced mathematics using technology. Mathematics Education Research Journal, 12, 210-230. Tall, D. (2001a). A child thinking about infinity. Journal of Mathematical Behaviour, 20, 7- 19. 210 Tall, D. (2001b). Natural and formal infinities. Educational Studies in Mathematics, 48, 1 99-23 8. Tall, D., & Tiroch, D. (2001). Infinity — The never-ending struggle. Educational Studies in Mathematics, 48, l 29- 136. Tall, D., & Vinner, S. (1981). Concept image and concept definition in mathematics with particular reference to limits and continuity. Educational Studies in Mathematics, 12, l 5 1-1 69. TIMSS (2002). Student Questionnaire: Grade 8. Prepared by the International Study Center at Boston College. Chestnut Hill, MA: Boston College. Tirosh, D. (1992). The role of students’ intuitions of infinity in teaching Cantorian theory. In D. Tall (Ed), Advanced mathematical thinking (pp. 199-214). Dordrecht, The Netherlands: Kluwer Academic. Thompson, D. R., & Rubenstein, R. N. (2000). Learning mathematics vocabulary: Potential pitfalls and instructional strategies. Mathematics Teacher, 93, 568-574. Tsamir, P. (2001). When ‘the same’ is not perceived as such: The case of infinite sets. Educational Studies in Mathematics, 48, 289-307. Tsamir, P., & Dreyfus, T. (2002). Comparing infinite sets — a process of abstraction: The case of Ben. Journal of Mathematical Behaviour, 21, 1-23. Thomas, G. (2005). Thomas ’ calculus (11th ed. Revised by M. Weir, J. Hass, & F. Giordano). NY: Addison Wesley. U.S. Department of Education. (2006). T he federal role in education. Retrieved October 8, 2006, from httpzllwwwed.gov/about/overview/fed/role.html Vinner, S. (1992). The role of definitions in the teaching and learning of mathematics. In D. Tall (Ed), Advanced mathematical thinking (pp. 65-81). Dordrecht, The Netherlands: Kluwer Academic. Vygotsky, L. S. (1978). Mind in society: The development of higher psychological processes. Cambridge, MA: Harvard University Press. Vygotsky, L. S. (1986). Thought and language. Cambridge, M.A.: MIT press. Wang, J., & Lin, B. (2005). Comparative studies on U.S. and Chinese mathematics learning and the implications for Standards-based mathematics teaching reform. Educational Researcher, 34(5), 3-13. Weller, K., Brown, A., Dubinsky, E., McDonald, M., & Stenger, C. (2004). Intimations of infinity. Notices of the American Mathematical Society, 51, 741-750. 211 Whimbey A., & Lochhead, J. (1982). Beyond problem solving and comprehension: An exploration of quantitative reasoning. Hillsdale, New Jersey: Lawrence Erlbaum Associates. Williams, S. R (1991). Models of limit held by college calculus students. Journal for research in Mathematics Education. 22(3), 219-236. Williams, S. R. (2001). Predications of the limit concept: An application of repertory grids. Journal for Research in Mathematics Education, 32(4), 343-367. Wolfe, R G. (1999). Measurement obstacles to international comparisons and the need for regional design and analysis in mathematics surveys. In G. Kaiser, E. Luna & I. Huntley (Eds), International comparisons in mathematics education (pp. 225-240). Philadelphia, PA: Falmer Press 212 3062 60 0 1293 0