$0 .9: n 1.} is g; L N UNIT Q Die teaching inSD'Uctors, m to students in SUC definition of limn Cany' a unit 0n 11' sections of PIECa unit included def; TWO SECtiong learning Strategy ABSTRACT LIMITS: A MASTERY LEARNING APPROACH TO A UNIT ON LIMITS OF SEQUENCES AND FUNCTIONS IN A PRECALCULUS COURSE AND ACHIEVEMENT IN FIRST SEMESTER CALCULUS by Douglas William Nance The teaching of limits to calculus students is a task faced by most college instructors. This study was an attempt to find a method of presenting limits to students in such a way that they would be prepared to work with a formal definition of limit of a function in a first semester calculus course. Specifi- cally, a unit on limits of sequences and limits of functions was taught in four sections of Precalculus Mathematics at Central Michigan University. This unit included definitions of both limit of a sequence and limit of a function. Two sections that received the unit on limits were taught using a mastery learning strategy. This consisted of (1) stating the instructional objectives, (2) presenting the unit of instruction, (3) administering a formative evaluation, (4) utilizing instructional alternatives, and (5) administering a summative evaluation. Advocates of this approach maintain that generally three fourths of the students can achieve at the same high level that only one fourth of the students usually achieve. This "achievement level" is referred to as the mastery level or c eighty-five percent receive a grade of attain this level at A unique aspet mastery level on I] These Students we: calcm118 the follow 0f the mastery leai TWO sections i received iDStrucu'c sections Were used limits. Performan Calculus I COUrse t to PrecalculuS Stud TICatmem €fo two ways, One Wa etalculus sectiox Douglas William Nance mastery level or criterion. Ordinarily, this level is between eighty and eighty-five percent or equivalently a criterion that would allow a student to receive a grade of A or B in a regular classroom situation. Students who attain this level are said to have "mastered" the material. A unique aspect of this study was to identify students who attained the mastery level on the summative evaluation but not on the formative evaluation. These students were given the label "delayed mastery" and their progress in calculus the following semester was analyzed to determine carry-over effects of the mastery learning strategy. Two sections of Precalculus students studied the same unit on limits but received instruction via an expository presentation. Five other Precalculus sections were used as a control group and received no instruction regarding limits. Performance of students from all nine sections was analyzed in the Calculus I course the semester following the presentation of the unit on limits to Precalculus students. Treatment effects on the affective domain elements were determined in two ways. One was by interviewing randomly selected students from the Precalculus sections. The other was by analyzing responses to a question- naire completed by Treatment and Control students enrolled in Calculus I. In addition to these analyses, enrollment figures in Precalculus and Calculus I for the years 1971, 1972, and 1973 were examined to see if the Treatment affected the percentage of Precalculus students enrolling in Calculus I. The effect at two stages c first. Student limits and (2) t dent provided :1 Findings 01 1. The mt the stu t0 thirt expositt 2- There v behveen here u between Control There w between COrltr'ol Douglas William Nance The effect of the treatment on achievement in Calculus I was analyzed at two stages of the course. Data from the test covering limits was used first. Student performance was measured on (1) the questions involving limits and (2) the total test scores. The semester percentage for each stu- dent provided the second set of data. Findings of the study include the following: 1. The mastery learning strategy resulted in sixty-five percent of the students attaining the mastery level of eighty percent compared to thirty-four percent of the students attaining that level in the expository treatment group. There was no significant difference in achievement in Calculus 1 between delayed mastery students and other mastery students. There was no significant difference in enrollment in Calculus 1 between students in the Treatment sections and students in the Control sections. There was no significant difference in achievement in Calculus I between students in the Treatment sections and students in the Control sections . LU UMTC LIMITS: A MASTERY LEARNING APPROACH TO A UNIT ON LIMITS OF SEQUENCES AND FUNCTIONS IN A PRECALCULUS COURSE AND ACHIEVEMENT IN FIRST SEMESTER CALCULUS by Douglas William Nance A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Secondary Education 1974 Iwould like ‘ dissertation poss Professor Jo adtice and gmdai Protessors ] doctoral commit Professor W Project. Last in 0rde tmist, ”Glen M, have enabled me ACKNOWLEDGMENTS I would like to thank the following individuals who helped make this dissertation possible: Professor John Wagner, advisor and Committee Chairman, for his advice and guidance during the last five years. Professors Joseph Adney, Julian Brandon, and William Fitzgerald, doctoral committee members, for their advice and encouragement. Professor William E. Lakey for his continued support of the research project. Last in order but first in thought, I would like to thank my wife and typist, Helen M. Nance. Her patience, encouragement, and perseverance have enabled me to complete this project. ii LIST OF TABLE LIST OF FIGL'R CHAPlER I. IbeII()I bCeex hias‘ Dela I-eve Disc State TABLE OF CONTENTS LIST OF TABLES ....................... LIST OF FIGURES . . . . ......... . ......... CHAPTER I. INTRODUCTION ............... . . . . . Need for Study ................... Mastery Learning .................. DelayedMastery ....... LevelofMaterial . . . . . . . . . ......... Discussion . . ...... . . ........... Statementonypotheses . . . . . . . . . . . . . . . Organization of the Dissertation . . ...... . . . II. REVIEW OF RESEARCH . . . . . ........... Limits . . . . ......... . . ........ MasteryLearning.................. Summary.................... Classification of Objectives . . . . . . . . . . . . . III. PROCEDURES PopulationandExperimental Design . . . . . . . . . . PersonsAssistingintheStudy............ iii Page xi 10 10 14 20 21 26 26 27 Mas For Con Inst Ev: Ins Su De W- Fth: Pt Page Mastery Learning Strategy. . . . . . . . . . . . . . 27 Formulation of Instructional Objectives: Treatments A and B O I O O O O O O I I O O O O O O O O O O O 28 Construction of Unit of Instruction: Treatments A and B . 30 Instruction: Treatments Aand B . . . . . . . . . . . 31 Quizzes............ ....... .. 32 Evaluation: TreatmentsAandB . . . . . . . . . . . 33 Wilson'sModel..................33 GradingtheTests ..... . . . . . . . . . . . 33 Diagnostic Procedures for TreatmentA . . . . . . . . 36 Instructional Alternatives: Treatment A. . . . . . . . 38 SummativeEvaluation................ 39 Delayed-Mastery Students . . ..... . . . . . . . 39 AnalysisofData. . . . . . ......... . . . . 39 IV. FINDINGS.......................44 PostHocTest...................44 MasteryLearning..................44 Summary....................50 Enrollment.....................S4 Summary....................S7. Withdrawals from Calculusl. . . . . . . . . . . . 57 AffectiveDomain..................58 Interviews....................58 Questionnaire.................. 61 iv Page Cognitive Domain . . ......... . ...... 62 TestonLimits..................62 Semester Average in Calculusl . . . . . . . . . . 70 Summary............ ........ 73 V. CONCLUSIONSANDIMPLICATIONS . . . . . . . . . . . 76 Summary of Procedures . . ..... . . . . . . . . 76 Results......................77 MasteryLearning................78 Enrollment ...... ...........78 AffectiveDomain.................79 CognitiveDomain................80 Delayed-Mastery..... ..... 82 Conclusions....................83 Implications for Education . . . . . . . . . . . . . . 84 InstructionalUnit................. 84 MasteryLearning.................84 SourcesofVariation 85 OtherComments................. 86 Suggestions for Further Research. . . . . . . . . . . 87 APPENDIX I.InstructionalUnit...................9O 11. Daily Classroom Record for TreatmentA . . . . . . . . lll III.Quizzes........................114 V IV. Summative Evaluations - Treatment B . . . . . . . . . . V. Formative Evaluation- TreatmentA. . . . . . . . . . . VI. Summative Evaluation - Treatment A. . . . . . . . . . . VII. Instructional Alternative Worksheets. . . . . . . . . . . VIII. Attendance Summary for Alternative Instruction Sessions. . IX. CalculusTests.. ...... ........... X. Description of Random Selection Procedure for Interviewees XI. Intervieruestions XII. Questionnaire Given to Calculus Students . . . . . . . . . XIII. Interview Responses Tabulated for Various Groupings of CellsoftheExperimentalModel. . . . . . . . . . . . . XIV. Cell Components of Chi Square Values for Questionnaire Itms I I I I I I I I I I I I I I I I I I I I I I I I I XV. Cell Components of Chi Square Values for Enrollment my8is I I I I I I I I I I I I I I I I I I I I I I I XVI. Calculus I Test Results and Final Percentages . . . . . . XVII. Contingency Tables for Chi Square Test Statistics Computed for the Sum of Items Two, Three, and Four of the Calculus I Test I I I I I I I I I I I I I I I I I I I I I I I I HBLIOGRAH-IY I I I I I I I I I I I I I I I I I I I I I I I I Page 115 117 119 120 124 125 130 131 132 133 134 138 139 143 145 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4,14 4,15 4.16 4.17 Analysis Formatj‘ Test For Form atj Test F0 Format SUmmat SUmmaI Summ at Test Ft Stimma Test F< Stimma Enronr Enronr Intel-vi, 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 LIST OF TABLES Analysis of A.C.T. Scores: Post Hoc Test . . . . . Formative Evaluation Item Results -- Treatment A -- Test Form C Formative Evaluation Item Results -- Treatment A -- Test Form C Formative Evaluation Scores: Treatment A Summative Evaluation Item Results -- Treatment A . Summative Evaluation Scores: Summative Evaluation Item Results -- Treatment B -- Test Form A Summative Evaluation Item Results -- Treatment B -- Test Form B Summative Evaluation Scores: Treatment A Treatment B Enrollment Summaries . . . . . . Enrollment Analysis Results . Interview Responses . . . . . Questionnaire Responses . . . Questionnaire Data . . . . . . Calculus 1 Test Item 1 -- Forms, A, B, and C Calculus I Test Item 2 -- Forms A, B,C,D,E Responses by Cells to Limit Items 2, 3, and 4 of the Calculus I Test Vii Page 45 46 47 48 49 50 51 52 53 55 56 59 63 64 66 67 68 4.19 4.20 4.21 4. 22 4.23 4. 24 4.1 14.2 4.3 4.4 4.5 Ah Analysis < Calculus I Group Me Scores . One-W ay Scheffe i Calculus Semeste EXPerin Analysi SCheffe Toni P Attenda Inter-Vi Chi Sqi Chi sq Galen] Chis: 4.18 4.19 4. 20 4.21 4. 22 4. 23 4. 24 A.l A.2 A.3 A.4 A.5 A.6 Analysis of Student Performance on Limit Items in calcmus I TeSt I I I I I I I I I I I I I I IIIIII Group Means and Standard Deviations for Calculus I Test scores I I I I I I I I I I I I I I I I I I I I I I I I One-Way Analysis of Variance for Calculus I Test Scores. . Scheffe Multiple Comparison Test for Equality of Means calcmus I TeSt I I I I I I I I I I I I I I I I I I I I Semester Averages by Groupings of Cells of the Experimerltal MOdel I I I I I I I I I I I I I I I I I I Analysis of Variance Table for Semester Averages by Cell . Scheffe Multiple Comparison Test for Equality of Means Total Percentage Grade for Calculus I . . . . . . . . . . Attendance Summary for Alternative Instruction Sessions. . InterviewResponses.................. Chi Square Values for Questionnaire Items . . . . . . . . Chi Square Values for Enrollment Analysis . . . . . . . . Calculus 1 Test Results and Final Percentages . . . . . . ChiSquare Values for CalculusITest . . . . . . . . . . viii Page 68 69 70 72 72 73 124 133 134 138 139 143 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.1 4.2 4.3 5.1 P0pulatic Instructi 1. W. W11 Classific Cujdeline Diagnosu- Room Ar Delayed I 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.1 4.2 4.3 5.1 LIST OF FIGURES Population and Experimental Design . . . . . Instructional Strategies for Treatment Sections J.W. Wilson's Taxonomy . . . . . . . . . . Classification of Test Items. . . . . . . . . Guidelines for Assigning Partial Credit , . . , Diagnostic Forms for TreatmentA . . . . . Room Arrangement for Small Group Sessions . Delayed Mastery Students. . . . . . . . . . Number of Students Selected for Interview by Group Summary of Interview Responses . . . . . . . . Analysis of Anxieties and Attitudes Toward Calculus I Summary of Questionnaire Results . . . . . . . . . Profile of Delayed Mastery Students . . . . . . . . Page 26 29 34 35 36 37 38 40 41 6O 61 65 82 CHAPTER I INTRODUCTION This study investigated a method of presenting the topic of limits to students. Specifically, a unit on limits of sequences and limits of functions was taught in four sections of Precalculus Mathematics at Central Michigan University (CMU). This differs from the current practice at CMU of teaching limits“ only in the calculus course. This approach is consistent with G. Rising'sl belief in presenting limits prior to calculus. It also gave a longer introduction to the definition of limit of a function and its subsequent use than is currently done at CMU. Need for Study The concept of "limit" is an essential part of a beginning calculus course. C.B. Allendoerfer said, "The essential idea in calculus is that of 112133 . . . "2 Support for the importance of limits is given by the fact that several basic calculus topics are defined in terms of them. In particular, continuity of functions, differentiation of functions, and integration of functions all use limits in their definitions. The central role of this concept makes it apparent that mathematicians "‘ The word 1imit(s) is imprecisely used and refers to the more specific topics of "limits of sequences" and "limits of functions". Since these are closely re- lated but nOt always taught in the same course, the general term "limit(s)" will be used to mean either or both, whichever is more appropriate for the context. 1 2 and mathematics educators should be concerned about finding the most effec- tive methods of presenting this topic to the beginning and prospective calculus student. The need for this concern was emphasized by R.G. Long in 1968 when he included in his "Report of the Cornell Conference", under topics for research, the following item: "In freshman calculus, what is the mechanism involved in acquisition of the limit concept ?"3 There are differing opinions as to when, where, and how limits should be taught. E.W. Ferguson, 4 D.W. Hight, 5 M. F. Hubley, 6 and G.R. Rising7 have supported the teaching of calculus (which includes limits) in the secon- 8 A. Beninati, 9 and dary schools. On the other hand, C. B. Allendoerfer, J. H. Neelley10 are opposed to introduction at that level. Another difference of opinion involves the amount of formal logical procedures used in present- ing the concept of limits. One approach uses a minimum of formal logic and avoids a precise definition, but attempts to give students an intuitive idea of the limit concept. Another approach utilizes a precise definition of limit and subsequent formal logical development leading to the proof of theorems involving limits. Since the definition of limits frequently employs the Greek symbols "¢ " (epsilon) and "5 " (delta), this is referred to as the (6 , J ) or rigorous approach. The intuitive and rigorous approaches exist as opposite ends of a spec- trum and most calculus instructors would place themselves somewhere between these extremes. J.R. Anderson, 11 for example, believes in an intuitive approach with an (6 .5 ) treatment postponed until advanced calculus. 3 Others such as C.B. Allendoerfer12 and R. P. Boas, Jr.l3 believe in starting ‘ with an intuitive approach and leading up to an (6 , J ) treatment in a begin- ning course. Mastery Learning Another feature of the study was that a mastery learning strategy was employed to teach two of the sections involved in the experiment. Histori- cally speaking, major mastery learning attempts date to the early 1900's. J.H. Block says, "As early as the 1920's there were at least two major attempts to produce mastery in students' learning. "14 Mastery learning consists of stating objectives, presenting the unit of instruction, adminis— tering a "formative” evaluation, providing feedback from this evaluation, utilizing alternative instructional techniques, and then administering a "summative” evaluation. The effectiveness of this strategy is indicated by J.H. Block in the following statement, "In general, three fourths of the students learning under mastery conditions have achieved to the same high standards as the top one-fourth learning under conventional, group-based instructional conditions. "15 A description of the aspects of mastery learning is given in Chapter II. * These terms are defined on pages 19-20 of this document. Delayed Master Some stude of this study. ' attain the mast: reach this level StUdents is a lit group 0i studen learning approe Level of ‘ . w Limit pro] learning techm Problems (Cha the material t: Applicatmn, 0 most for Sch. ‘er leirrung 1191113. A dis Delayed Mastery Some students will be identified as "delayed-mastery" for the purposes of this study. These will be the students in the mastery treatment group that attain the mastery level (80 percent) on the summative evaluation but do not reach this level on the formative evaluation. The identification of these students is a unique aspect of this study. Subsequent achievement of this group of students will be analyzed to determine what effect the mastery learning approach in Precalculus had on their performance in Calculus 1. Level of Material Limit problems can be of many levels of difficulty. Since mastery learning techniques have proven to be effective for lower level (Computation) problems (Chapter II), an additional aspect of this study was to categorize the material to be mastered by the treatment groups at the Comprehension, Application, or Analysis levels in the cognitive domain of J.W. Wilson's model for school learning. Part of the analyses will then be to see if mas- tery learning can be effectively employed in the learning of higher level items. A discussion of the components of this model are given in Chapter 11. Discussion Nine sections of precalculus students at Central Michigan University constituted the population for this experiment. Each section contained 5 approximately thirty students. Five of these sections were used for control. Of the remaining four, two were administered a section on limits of se- quences and limits of functions via a classroom lecture method. The remain- ing two sections were administered the same unit of material via a mastery learning strategy. Several reasons were considered when selecting the groups for treatment or control. Both mastery learning sections were taught by the experimenter. The other two treatment sections were taught by Dr. Douglas D. Smith who was the only other staff member at CMU teaching two sections of Precalculus Mathematics during the semester the experiment was conducted. The other five sections were used as a control group. Since these were taught by five different individuals, it was decided these would be the ones most appropriate for control since any other assignment of treatment groups would have meant at least three instructors working with treatment groups. The results of this study involved both the affective (interest, attitude, etc.) and cognitive (achievement) domains. The affective domain results were checked by interviews, questionnaires, enrollments, and retention figures. The cognitive domain results were obtained from the calculus course given the semester following the teaching of the treatment units. Results of the test covering the section on limits were analyzed and achieve- ment in the entire course was examined. Statement of Hypotheses The hypotheses to be studied are: l. A mastery learning strategy, employed on a unit of limits of sequences and limits of functions, will result in no significant difference between the proportion of students achieving the mastery level in a mastery learning situation and the proportion of students achieving the mastery level in an expository classroom situation. A unit on limits in Precalculus will not affect attitudes (a) prior to taking Calculus I (b) during Calculus I. The analysis of this hypothesis will be qualitative and will consist of reporting results of interviews and questionnaires completed by students involved in the study. There will be no significant difference between the percentage of students enrolling and remaining in Calculus I after having had a unit on limits and the percentage of students from the Control group enrolling and remaining in Calculus I. There will be no significant difference in achievement in Calculus I between students in the treatment groups that achieve mastery and those that did not achieve mastery. There will be no significant difference in achievement in Calculus I between delayed mastery students and other mastery students in the treatment groups. 7 6. An introduction to limits prior to Calculus I will result in no significant difference in achievement (a) on the work with limits in Calculus I (b) in the first semester of Calculus I. This hypothesis was tested by examining test scores and semester averages of students involved in the study who enrolled in Calculus I. Hypotheses l, 3, 4, 5, and 6 were tested at the significance level of oL=.05. Orggnization of the Dissertation The remainder of the dissertation is divided into four chapters. Chapter 11 contains a review of relevant literature. Material involving when, where, and how limits are taught is examined. Explanations of and references to mastery learning and learning models are included. Chapter 111 describes the procedures used during the experiment. Included therein is the experi- mental model. Chapter IV contains the findings of the study and Chapter V gives the conclusions and implications. FOOTNOTES -- CHAPTER I lRising, Gerald R. "Some Comments on Teaching of the Calculus in Secondary Schools", The American Mathematical Monthly, March, 1961, 68:287-290. 2Allendoerfer, C. B. "The Case Against Calculus", The Mathematics Teacher, Nov. 1963, 56:482-485, p. 484. 3Long, R.G. "Report of the Cornell Conference on Mathematics Education", 1968. 4Ferguson, Eugene W. "Calculus in the High School", The Mathematics Teacher, Oct. 1960, 53:451-453. 5Hight, Donald W. "The Limit Concept in the Education of Teachers", American Mathematical Monthly, Vol. 70, 1963, pp. 203-205. 6Hubley, Martin F. and Charles W. Maclay, "An Experiment in High School Calculus", The Mathematics Teacher, Nov. 1970, pp. 609-612. 7Rising, Gerald R. "Some Comments on Teaching of the Calculus in Secondary Schools", The American Mathematical Monthly, March 1961, 68:287-290. 8Allendoerfer, C.B. "The Case Against Calculus", The Mathematics Teacher, Nov. 1963, 56:482-485. 9Beninati, Albert, "It's time to take a closer look at high school calculus", The Mathematics Teacher, Jan. 1966, pp. 29-30. loNeelley, J.H. "A Generation of High School Calculus", The American Mathematical Monthly, Dec. 1961, 68:1004-1005. 11Anderson, John Robert, "A Comparison of Student Performance in a One Year Freshman College Calculus Course Resulting from Two Different Methods of Instruction", Unpublished Ph.D. Dissertation, Purdue University, 1970. 12Allendoerfer, C.B. "The Case Against Calculus", The Mathematics Teacher, Nov. 1963, 56:482-485. l3Boas, R.P. , Jr. "Calculus as an Experimental Science", American Mathematical Monthly, Vol. 78, June-July, 1971, pp. 664-667. 8 9 14Block, James H. (ed.) Mastery Learning: Theory and Practice, Holt, Rinehart and Winston, Inc., New York, 1971, p. 3. ls'Ibid. CHAPTER H REVIEW OF RESEARCH Limits A college level course in beginning calculus is concerned with the concepts of limits of functions, continuity of functions, differentiation of functions, and integration of functions. Limits of functions is perhaps the most important of these since the others are defined in terms of them. R.V. Lynch referred to limit as . .the central concept of calculus. . . "1 These thoughts were supported by D. Kleppner and N. Ramsey when they said, "The idea of limit. . .is at the heart of calculus. . . "2 and "Once you have a real feeling for what is meant by a limit you will be able to grasp the ideas of differential calculus quite readily. "3 Further support for the importance of limits was given by D. W. Hight when he said, "It is the introduction of limits that allows one to proceed from elementary mathema- tics to a study of calculus and all its ramifications. "4 There are several approaches to presenting the concept of limits to students of calculus. These range from a brief discussion of the concept with some examples (frequently called the "intuitionist" approach) to a development based on precise definition of limit and subsequent logically developed proofs and applications of theorems. The question of how much rigor should be applied in developing the concept of limits has been discussed by several people. C. B. Allendoerfer has said, "All too often we begin the 10 11 course with an off-hand reference to limits as something too hard for the students to really understand. . ."5 He continues with, "There are those, however, who begin the course with a brief, but full dress, treatment of limits using the epsilon-delta technique. This almost universally is wasted on the class, for they are confronted with a diffith new idea without an intuitive preparation. "6 A study by J.R. Anderson7 compared two approaches to presenting limits; one used the (E , 5 ) definition and subsequent development while the other used an intuitive development with the ( é , S ) definition coming in advanced calculus. The second method was found to be Significantly better with respect to achievement but there was no change in attitude as a result of method. Included in the concluding remarks of this study was, "Evidently neither method could make the (G ,5 ) notation and proof any more palatable for the students. "8 T. H. McGannon, in a more general study,9 examined a rigorous versus intuitive approach to calculus. Among the results of the analyses were the following: there is no difference between the rigorous method and the intuitive method of teaching calculus with respect to achieve- ment of (a) a proficiency in manipulative skills, (b) an understanding of the fundamental concepts, and (c) an ability to make practical applications of the principles learned. The fundamental nature of the limit concept in calculus and the lack of agreement regarding its presentation have resulted in attempts to teach limits prior to calculus. Gerald Rising supports this idea and recommends 12 having such a unit taught in a high school course. He says, "Students can spend a substantial amount of time on two topics which most college teachers will agree deserve more time than they are able to allot to them. These two topics are limits and the definition of the derivative. Rather than gloss over these topics superficially in a lesson or two, as is so often done in college courses, the secondary program offers the possibility of spending two or three weeks on each topic. "10 He continues by saying, "By solid teaching of these topics [limit, derivative] the secondary teacher can help remove what I believe to be two of the toughest hurdles to mathematics students in the college program. ,,11 Rising is supported by D. W. Hight who says, "The teaching of the con- cept of a limit should begin in the secondary schools. . . "12 and "The greatest gap between the secondary school mathematics prOgram and that of the col- leges seems to be due to the present treatment of topics that involve limits. "13 Hight's belief that limits should be taught in secondary schools is a result of a stronger belief that limits should be taught prior to calculus. He says, . .it is important that students have a good understanding of the concepts of limit prior to entering calculus. . ."14; . . the students need a gradual introduction to the limit concept in order to grow in mathematical maturity and gain a readiness for calculus. "15; and, "If he is unacquainted with the limit concept, he can hardly be prepared for calculus when the definitions of both the derivative and the integral involves limits. "16 A concern for acquisition of the limit concept and success in calculus l3 prompted the author to initiate this study which investigated some of the aforementioned variables. Currently at Central Michigan University, limits are taught only in the calculus course and are developed using a rigorous (6 , S ) approach. Many of the calculus students did not have a section on limits in their high school mathematics classes; consequently they were receiving instruction regarding limits that, according to Allendoerfer, is ". . .almost universally wasted on the class. . ."17 The ideas of Rising, Hight, and others were implemented in this study by including a unit on limits of sequences and limits of functions in four sec- tions of CMU's Precalculus course. This unit included more than an intuitive presentation of the concept of limit. It contained precise definitions (involving [5 , S ] notation) and subsequent development of several theorems regarding limits. This approach is supported by the work of D. T. Coon18 who, in a study involving the intuitive concept of limit possessed by precalculus students, found there was no significant correlation between intuitive knowledge of limit and achievement in calculus. One aspect of this study was the use of a special instructional strategy in two of the treatment sections. This strategy consisted of teaching the unit on limits using a "mastery learning" approach. Various aspects of this approach are analyzed in the next section. Mastery Learni: Mastery lee students can lea variables are id StudentS, perha them, and it is students to mas mine what is m« materials Whicl master-3:519 The Variab 11) aptitude fOr (3) 31311er to Un‘ l4 Mastery Learning Mastery learning is an educational strategy based on the premise that students can learn almost all of the material presented to them if certain variables are identified and controlled. Benjamin S. Bloom said, "Most students, perhaps over 90 percent, can master what teachers have to teach them, and it is the task of instruction to find the means which will enable students to master the subject under consideration. A basic task is to deter- mine what is meant by mastery of the subject and to search for methods and materials which will enable the largest proportion of students to attain such ..19 mastery. The variables affecting learning were identified by John B. Carroll20 as (l) aptitude for particular kinds of learning, (2) quality of instruction, (3) ability to understand instruction, (4) perseverance, and (5) time allowed for learning. Carroll believes that, . .if the students are normally dis- tributed with respect to aptitude, but the kind and quality of instruction and the amount of time available for learning are made appropriate to the charac- teristics and needs of each student, the majority of students may be expected to achieve mastery of the subject. " Several mastery learning strategies have been devised which attempt to control the variables described by Carroll. Bloom, when discussing what his group at Chicago had been doing, said, "Our approach has been to supple- ment regular group instruction by using diagnostic procedures and alternative 15 instructional methods and materials in such a way as to bring a large propor- tion of the students to a predetermined standard of achievement. In this approach, we have tried to bring most of the students to mastery levels of achievement within the regular term, semester, or period of calendar time in which the course is usually taught. "22 Samuel T. Mayo23 outlined a more descriptive procedure when he summarized a national meeting that dealt with the topic of mastery learning. He indicated a mastery learning strategy should include the following. (1) Inform students about course expectations, even lesson expectations or unit expectations, so that they view learning as a cooperative rather than as a competitive enterprise. (2) Set standards of mastery in advance; use prevailing standards or set new ones and assign grades in terms of performance rather than relative ranking. (3) Use short diagnostic progress tests for each unit of instruction. (4) Prescribe additional learning for those who do not demonstrate initial mastery. (5) Attempt to provide additional time for learning for those persons who seem to need it. The success of mastery learning strategies has been documented in several studies. Peter W. Airasian used a mastery strategy in a graduate- level course in test theory. According to his summary of the study, the method used produced successful results. He said, "The main result was l6 striking. Whereas in the previous year only 30 percent of the students received an A grade, 80 percent of the sample achieved at or above the pre- vious year's A grade score on a parallel exam and thus received A's. "24 Kenneth M. Collins employed a mastery strategy in the teaching of four college mathematics courses for freshmen. Concerning the results of his study, he said, "In the modern algebra courses, 75 percent of the mastery compared to only 30 percent of the non-mastery students achieved the mastery criterion of an A or B grade. The calculus classes' results were similar: 65 percent of the mastery compared to 40 percent of the nonmastery students achieved the criterion. "25 The results of other studies using mastery strategies are summarized in the following: (1) Fred S. Keller26 had 65 percent to 70 percent of the class receive A's or B's; (2) Mildred E. Kersh27 had 75 percent of a class achieve mastery as compared to 19 percent that achieved mastery in a con- trol class; (3) Hogwan Kim28 had results that indicated 74 percent of the experimental group compared to only 40 percent of the control group attained the mastery level; and (4) Samuel T. Mayo, Ruth C. Hunt, and Fred Tremmel29 found when working with students in an introductory statistics course that 65 percent of the mastery learning students received a grade of A in contrast with 5 percent of the comparison group. Mastery learning strategies accomplish more than having a high per- centage of the students achieve at levels formerly attained by only a small percentage of the students. There are several affective consequences of such strateg.‘ a stude: others 17 strategies. For example, J.H. Block says, "In a system with few rewards, a student may not be rewarded no matter how well he learns so long as others learn better. If this situation occurs repeatedly, he is likely to eventually stop trying to learn well. In a system of unlimited rewards, by contrast, a student who learns well can be rewarded even though others may learn still better. Successful and rewarding learning experiences are likely, in turn, to kindle a desire to continued learning excellence."30 Benjamin S. Bloom, 31 when discussing mastery learning, lists the following affective consequences: (1) students develop more interest for the courses they master, (2) students develop a more positive self concept, (3) mastery learning can develop a lifelong interest in learning. In addition to these consequences, Bloom says, "Mastery learning can be one of the more powerful sources of mental health."32 The success of mastery learning strategies induced the author to use such a strategy in one of the treatment sections of this experiment. It was based on the outline presented by S. T. Mayo. In accordance with item 1 of his outline, terminal objectives (unit expectations) were selected prior to starting the experiment. The difficulty of such a selection is documented by K. Collins when he says, "Specification of objectives is perhaps the most difficult variable to properly prepare. "33 The next step in preparing a mastery strategy is to select standards of mastery. With regard to this, Bloom says, "While absolute standards care— fully worked out for a subject are recommended, they are often difficult to set. One metl in a particular grading standa- used."34 Alo- Objective rule "A. . . standar. for the subjec Under master ms‘ery teacl med studex be useful ma: "The empiric of the Skills : COgru'u'Ve and This Work a1 or nearly all expectation i may 11an “la IOWal'd the 1E 18 set. One method might be to use standards derived from previous experience in a particular course. For example, grades for one year might be based on grading standards arrived at the previous year if parallel examinations are used."34 Along these same lines, Block says, "There are no hard and fast objective rules for setting mastery grading standards. "35 He further says, "A. . .standard setting method is to transfer existent grading standards set for the subject under non-mastery learning conditions to the courses taught under mastery conditions. Standards from previous or concurrent non- mastery teachings of the subject can be used. Generally, scores which earned students learning under non-mastery conditions A's and B's seem to be useful mastery grading standards. "36 Block supports Bloom by saying, "The empirical work to date suggests that if students learn 80 to 85 percent of the skills in each unit, then they are likely to exhibit maximal positive cognitive and affective development as measured at the subject's completion. This work also suggests that encouraging or requiring students to learn all or nearly all (90 to 95 percent) of each unit, besides being an unrealistic expectation in terms of student and teacher time and effort (Bormuth, 1969), may have marked negative consequences for student interest in and attitudes toward the learning (Block, 1970; Sherman, 1967). "37 The classroom instructional techniques for a mastery learning situation do not have to differ from what a teacher would ordinarily employ. With regard to this, Bloom says, "In the work we have done, we have attempted to have the teacher teach the course in much the same way as previously. 19 That is, the particular materials and methods of instruction in the current year should be about the same as in previous years. "38 It is the belief of Bloom and others of his group that this is the only way mastery learning can be effectively spread. He feels that if extensive retraining of teachers 18 required, then the necessary effort will not be expended by the teachers. The next step in formulating a mastery learning strategy is the creation of diagnostic progress tests. These have been labeled "formative evalua- tions" by Michael Scriven. 39 According to Airasian, "Formative evalua- tions seek to identify learning weaknesses prior to the completion of instruc- tion on a course segment--a unit, a chapter, or a lesson. The aim is to foster learning mastery by providing data which can direct subsequent or corrective teaching and learning. "40 Another description of the purpose of formative evaluations is given by Bloom when he says, "For those students who have thoroughly mastered the unit, the formative tests should reinforce the learning and assure the student that his present mode of learning and approach to study is adequate. . . For students who lack mastery of a particu- lar unit, the formative tests should reveal the particular points of difficulty-- the specific questions they answer incorrectly and the particular ideas, skills, and processes they still need to work on. "41 The formative evaluations should be followed by diagnostic reports for each student. Learning difficulties indicated on these reports are to be cor- rected by instructional alternatives. A variety of alternatives will provide for some of the learning variables given by Carroll (page 14). Block lists the follovin Blo by his I STOUps . and to h and " likely tc effectht 20 following "learning correctives" : 42 (1) Reteaching (2) Small group problem sessions ( 3) Individual tutoring (4) Alternative learning materials (a) Alternative textbooks (b) Workbook and programmed instruction (c) Audio-visual materials ((1) Academic games and puzzles Bloom strongly advocates the small group problem sessions as evidenced by his remarks, "The best procedure we have found thus far is to have small groups of students. . .review the results of their formative evaluation tests and to help each other overcome the difficulties identified on these tests. "43 and, "Where learning can be turned into a cooperative process with everyone likely to gain from the process, small group learning procedures can be very effective. " 44 The last phase of a mastery learning strategy is administration of the "summative evaluation". This is the phrase used by Scriven45 for the test given to determine how well the students have "mastered" the objectives specified earlier in the unit of instruction. Summary: The mastery learning strategy used in one of the treatment groups of this experiment is based on common aspects of the various strate- gies previously mentioned and incorporated suggestions made concerning the compo Classi tional this st n0t su Classi: Benjan may fj bel‘I'ng mat, I 21 components of such strategies. A schematic diagram is given in Figure 3. 2. Classification of Objectives A successful mastery learning strategy requires specification of educa- tional objectives for the material being taught. Since one of the purposes of this study was to foster better "understanding" of the limit concept, it was not sufficient to specify the educational objectives; it was also necessary to classify them according to the type of learning involved. According to '9 Benjamin 8. Bloom, . . .a teacher, in classifying the goals of a teaching unit, may find that they all fall within the taxonomy category of recalling or remem- bering knowledge. Looking at the taxonomy categories may suggest to him that, for example, he could include some goals dealing with the application of this knowledge and with the analysis of the situations in which the knowledge is used. "46 The taxonomy used for classifying objectives in this study is James W. Wilson's model. 47 The basic categories in the cognitive domain are: (A) Computation, (B) Comprehension, (C) Application, and (D) Analysis. A result of the use of Wilson's taxonomy was the inclusion of objectives at the Comprehension, Application, and Analysis levels of behavior. A c0py of this taxonomy is contained on page 34. FOOTNOTES -- CHAPTER II lLynch, Ransom V. A First Course i_n’ Calculus, Ginn and Company, New York, 1964, p. 157. 2Kleppner, Daniel and Norman Ramsey, (Eick Calculus, John Wiley and Sons, Inc., New York, 1965, p. 53. 3Ibid. 4I-Iight, Donald W. "The Limit Concept in the Education of Teachers", American Mathematical Monthly, Vol. 70, p. 203. 5Allendoerfer, C.B. "The Case Against Calculus", The Mathematics Teacher, Nov. 1963, 56:482-485, p. 484. 6mm. 7Anderson, John Robert, "A Comparison of Student Performance in a One Year Freshman College Calculus Course Resulting From Two Different Methods of Instruction", Unpublished Ph.D. Dissertation, Purdue University, 1970. 8Anderson, John Robert, "A Comparison of Student Performance in a One Year Freshman College Calculus Course Resulting From TWO Different Methods of Instruction", Dissertation Abstracts, Vol. 31, p. 3980A. 9McGannon, Thomas Herbert, "A Comparison of Two Methods of Teaching Calculus With Special Inquiry Into Creativity", Unpublished Ph. D. Dissertation, Northwestern University, 1970. 10Rising, Gerald R. "Some Comments on Teaching of the Calculus in Secondary Schools", The American Mathematical Monthly, March, 1961. 68:287-290, p. 289. nlbid. 12Hight, Donald W. "The Limit Concept in the Education of Teachers", American Mathematical Monthly, Vol. 70, 1963, pp. 203-205, p. 204. 131m. 141mm, p. 203. 22 IS Americ 161: I7 Teache: 18 by Pre-e Achieve HI. K mags . 1968. 23 15Hight, Donald W. "The Limit Concept in the Education of Teachers", American Mathematical Montlgy, Vol. 70, 1963, pp. 203-205, p. 204. “mm. l7Allendoerfer, C.B. "The Case Against Calculus", The Mathematics Teacher, Nov. 1963, 56:482-485, p. 484. 18Coon, Dorothy Trautman, "The Intuitive Concept of Limit Possessed by Pre-Calculus College Students and Its Relationship With Their Later Achievement in Calculus", Dissertation Abstracts, Vol. 33, p. 1537A. 19Bloom, Benjamin S. "Learning for Mastery", UCLA-CSEIP Evaluation Comment, 1, No. 2, 1968, p. 1. 20Carroll, John B. "A Model of School Learning", Teachers College Record, 64, 1963, pp. 723-733. ZlBloom, Benjamin S. "Learning for Mastery", UCLA-CSEIP Evaluation Comment, 1, No. 2, 1968, p. 4. 271de p. 7. 23Mayo, Samuel T. Measurement 32. Education: Mastery Learning and Mastegy Testigg, National Council on Measurement in Eudcation, East Lansing, Michigan, 1970. 24Block, James H. , (ed.) Mastery Learning: Theory ;an_d Practice, Holt, Rinehart and Winston, Inc., New York, 1971, p. 98. 251mm, p. 111. 26Keller, Fred S. "Goodbye, Teacher. . .", Journal 2f Applied Behavior Analysis, _1_, 1968, pp. 79-89. 271(ersh, Mildred E. "A Strategy for Mastery Learning In Fifth-Grade Arithmstic", Unpublished Ph.D. Dissertation, University of Chicago, 1970, Reported in Mastegy Learning: Theogy___ and Practice by J.H. Block. 28Kim, Hogwan, et. al. The Mastery Learmn rnigg Project i_n t_h__e Middle Schools, Seoul: Korean Institute for Research in the Behavioral Sciences, 1970. Reported in Mastery LearniggtTh eo_1_'y _a_nd Practice by]. H. Block. 29Mayo, Samuel T. , et.al. "A Mastery Approach to the Evaluation of Learning Statistics", National Council on Measurement in Education, Chicago, Ill. , 1968. 30I Master Rinehm 31E Comme 321 33( Master} Annual 34B COmm e] \ 35B Masten ms; 361i ‘ 3711 388: c . m 39S 24 30Block, James H. "Operating Procedures for Mastery Learning", Mastggy Learning. Theory and Practice, Edited by J. H. Block, Holt, Rinehart and Winston, Inc., Chicago, 1971, p. 65. 31Bloom, Benjamin S. "Learning for Mastery", UCLA-CSEIP Evaluation Comment, 1, No. 2, 1968, pp. 10-11. 321mm, p. 11. 33Collins, Kenneth M. "An Investigation of the Variables of Bloom's Mastery Learning Model for Teaching Mathematics", Paper presented at the Annual Meeting of the Amer. Ed. Res. Asso. , Chicago, 1972. (ERIC 065 596) 34Bloom, Benjamin S. "Learning for Mastery", UCLA-CSEIP Evaluation Comment, 1, No. 2, 1968, p. 8. 35Block, James H. "Operating Procedures for Mastery Learning", Masteg Learning: Theory and Practice, Edited by J.H. Block, Holt, Rinehart and Winston, Inc., Chicago, 1971, p. 68. 361.2411.- 371mm, p. 70. 38Bloom, Benjamin S. "Learning for Mastery", UCLA-CSEIP Evaluation Comment, 1, No. 2, 1968, pp. 8-9. 39Scriven, Michael. "The MethodOIOgy of Evaluation", Perspectives 9i Curriculum Evaluation, Edited by Robert Stake, Chicago: Rand McNally and C0,, 1967, p. 7. 4OBlock, James H. (ed.) Mastegy Learnigg: Theogy and Practice, Holt, Rinehart and Winston, Inc., New York, 1971, p. 79. 41Bloom, Benjamin S. "Learning for Mastery", UCLA-CSEIP Evaluation Comment, 1, No. 2, 1968, p. 9. 42Block, James H. (ed.) Mastery Learning: Theory 329 Practice. Holt, Rinehart and Winston, Inc., New York, 1971, pp. 71-73. 43Bloom, Benjamin S. "Learning for Mastery", UCLA-CSEIP Evaluation Comment, 1, No. 2, 1968, p. 10. 4‘I‘Ibid. , p. 5. 5 . SCI'IVI and C0,, 19¢ 46810011 1956, p. 2. 25 45Scriven, Michael, "The Methodology of Evaluation", Perspectives 3f Curriculum Evaluation, Edited by Robert Stake, Chicago: Rand McNally and Co., 1967, p. 7. 46Bloom, Benjamin S. , et.al. (eds.) Taxonomy 3f Educational Ogjec- tives, Handbook 5 Cognitive Domain, New York: David McKay Co. , Inc. , 1956, p. 2. 47Bloom, Benjamin S. , et.a1. Handbook 93 Formative and Summative Evaluation at: Student Learning, McGraw-Hill Book Company, New York, 1971, p. 646. CHAPTER III PROCEDURES Population and experimental design The population for this study consisted of all students in nine sections of Precalculus Mathematics at Central Michigan University during the Fall Semester of the 1973-74 Academic Year. The study involved two treatment groups and a control group. Treatment A consisted of teaching a unit on limits of sequences and limits of functions to two of these sections using a mastery learning strategy as described on page 29. Treatment B consisted of teaching the same unit to two other sections but without employing a mas- tery learning approach. The remaining five sections were used as a control group and received no instruction regarding limits. The experimental design is given in Figure 3.1. Treatment A Treatment B Control n = 60 n = 61 n = 152 Maste n = 39ry Non- Non- mastery Mastery mastery (NNM) (SM) (SNM) (C) Early Delayed n = 21 n _._ 21 n = 40 mastery mastery (NEM) (NDM) n = 5 n = 34 FIGURE 3.1 Population and Experimental Design 26 Persons Assi: Three pe E. Lakey, wh all materials iors for Trea Douglas D. Sr reviewed the 3 formative eva Student, who , between the fc ment A. W SpeCts fmm t1 27 Persons Assisting in the Study Three persons assisted in some aspect of this study. Professor William E. Lakey, who currently teaches the Calculus I classes at CMU, reviewed all materials used in Treatments A and B, helped select the terminal behav- iors for Treatment A (page 28), and conducted some interviews. Professor Douglas D. Smith taught the two sections that received Treatment B. He also reviewed the instructional materials and assisted in the construction of the formative evaluations. The third person was Dave Rajala, an undergraduate student, who was used as a resource person during the small group sessions between the formative and summative evaluations for the students in Treat- ment A. Mastery Learning Strategy The mastery learning strategy used in Treatment A differed in some re- spects from the strategydescribed by S. T. Mayo in Chapter 11. One differ- ence was that the strategy was employed on a unit of instruction rather than the entire course. Consequently, only one formative evaluation was admin- istered. Secondly, students were not informed of all terminal objectives prior to the start of the unit because of the terminOIOgy involved. They were, however, informed of the objectives as soon as the required notation and terminOIOgy were introduced. For example, objective 4 (page 28) was stated after the definition for limit of a sequence was given. A third variation was that the iten Application, Figure . used in the t had to recor. to achieve m I“‘Ol'mulation \ The obje mm by Pro. Unit on limits (1) Give Part 28 that the items to be mastered would be classified in the Comprehension, Application, or Analysis levels of James W. Wilson's learning model.1 Figure 3. 2 is a schematic representation of the instructional strategies used in the treatment sections of this study. Students in Treatments a and B had to record a score of at least 80 percent, as suggested by J.H. Block, 2 to achieve mastery of the unit. Formulation of Instructional Objectives: Treatments A and B The objectives for the unit of study in Treatments A and B were estab- lished by Professor Lakey and the author. At the conclusion of studying the unit on limits, the students were expected to be able to do the following: (1) (2) (3) (4) (5) (6) (7) Given a sequence (function) that does not have a limit, indicate what part of the definition it fails to satisfy. Give an example of a sequence (function) that does not have a limit and include explanation. Given a real number, be able to produce a nonconstant sequence (function) whose limit is that real number and include explanation. When working with sequences, find the associated N 5 for a particular e . When working with functions, find the associated 6" for a particular 6 . Determine limits of sequences using the results of theorems. Determine limits of functions using the results of theorems. 29 Treatments A and B 4L Construction of unit of instruction: Treatments A and B Formulation of instructional objectivesJ Presentation of tructional objectives: Treatment A Instruction: Treatments A and B .L Evaluation: - Treatment B - Summative flEnd of Treatment B J Treatment A - Formative ' 3L [Diagnostic procedures for Treatment A J. Instructional alternatives: Treatment A 1. Supplementary instruction ‘ 2. Small-group sessions 3. Individual tutoring 4. Supplementary reading L [ Summative evaluation: Treatment Aj _ L _ [ End of Treatment A J *— FIGURE 3. 2 Instructional Strategies for Treatment Sections (8) Prove a for limf (9) Prove a indepei Objectives Wilson's mode] 0f Previously s For example, 9 hm BX“ “75 These Can 110‘ 30 (8) Prove a given sequence has a particular limit using the definition for limit of a sequence. (9) Prove a given function has a limit at a particular value of the independent variable using the definition for limit of a function. Objectives six and seven are classified in the application level of Wilson's model. Satisfactory performance would require appropriate use of previously stated theorems to determine limits of sequences (functions). For example, . 2 2 11m (3x + 2) 3x + 2 x-—)O . . . . l = - 11m t of uotient of functions x—DO 3-1 £30034) 1 ‘1 lim 3x2 + lit-:10 2 £4 1 x . limo xz _ lim (4) limit of sums of functions 1"" x—tO These can now be simplified by previous work and Other limit theorems to obtain Construction of Unit of Instruction: Treatments A and B The unit of instruction for Treatments A and B was compiled by the author. Ideas, order of presentation, and problems were obtained from the following: (1) Limits and Continuity by W.I(. Smith;3 (2) Limits: A Transi— 5 tiongCalculus by O.L. Buchanan, Jr. ;4 (3) Sguences by K.E. O'Brien; (4) Calculus f_o_i Mme the instruction Instruction: '1 \— The expe: ninth week of sider several They then an were refined given as f011< a p< Not 31 6 (4) Calculus for College Students by M.H. Protter and C.B. Morrey, jr. ; and (5) The Advanced Calculus 9_r One Variable by D.R. Lick.7 A copy of the instructional tmit is located in Appendix 1. Instruction: Treatments A and B The experimental unit for Treatments A and B was started during the ninth week of a fifteen-week semester. It began by having the students con- sider several examples of sequences, some of which did not have limits. They then attempted to define when a sequence has a limit. These attempts were refined by the use of counterexamples. Eventually the definition was given as follows: Definition: A sequence {any has a limit L if for each 6 > 0, there is a positive integer N such that if n) N, then [an - LI ( 6 . Notation: lim a = L n-toe H To better understand the 6 - N relationship, students were asked to find an N that would "work" for a particular value of 6 and a particular sequence. The smallest value of N that satisfied the definition for a given 6 was re- ferred to as the "N associated with the given a " and was denoted N6 . After finding several N6 '5, the students examined a proof of the statement lim l 119’ n+1 = 0 that utilized the definition given above. The students next considered more complicated sequences. For example, 2 + they were asked to evaluate lim flit—n . The difficulty of finding limits nw 32 for these sequences made them realize the necessity for theorems that would allow them to evaluate such limits. Six theorems concerning limits of se- quences were then stated, two of which were proven by using the definition. (See pages 95 and 96 of Appendix I ). Limits of functions were studied next. Examples were used to illustrate notation and the intuitive concept. Students were then asked to formulate a definition for the limit of a function at a particular value of the independent variable. Eventually the definition was given by the instructor as follows: Definition: The function f(x) has limit L as x approaches a if for each é } OthereisaJ } Osuchthatif0( lx-aIL J , then [f(x) - L, ( é . Notation: lim f(x) = L H a After several examples and problems were studied, the need for theorems was again noted by considering limits of more complicated functions. Six theorems were then stated, three of which were proven. (See pages 105 to 107 of Appendix 1) Students completed study of the experimental unit by evaluating the limits of functions at indicated values of the independent variable and attempting proofs of some results. A daily classroom record for Treatment A is available in Appendix II. Quizzes: A study by Merrill, M8 has shown that specific review following incorrect responses makes students' learning increasingly efficient. This result was implemented in Treatment A by administering six 33 instructional quizzes during the teaching of the unit. The specific review was then accomplished by working the problems immediately after the class had completed them and by providing written comments on the quiz papers that were returned to the students. These quizzes were not used as part of the mastery evaluation or grading procedure. They consisted of one problem each and the students were allowed at most ten minutes to work on them. If students were absent on the day a quiz was given, they were asked to work it outside of class and hand it in so appropriate comments could be made. These quizzes are listed in Appendix III. Evaluation: Treatments A and B The unit of instruction for Treatments A and B required nine instructional days. An evaluation was given on the tenth day. These were summative evaluations in Treatment B and formative evaluations in Treatment A. A seven-item test was used for the fifty-minute testing period. Parallel tests were randomly assigned to the treatment sections. Copies are available in Appendices IV and V. Wilson's Model: Part of this study was to examine the mastery of items at specified levels of a learning model. James W. Wilson's model, given in Figure 3. 3, was used and the items were tested at the Comprehension, Appli- cation, and Analysis levels. Figure 3. 4 indicates the classification of items in the tests. Grading the tests: The tests in Treatments A and B were graded by the m>p~ZOOU m>pUm~h~h~V m 34 BEHAVIOR g A.l Knowledge of specific facts o 3 A. 2 Knowledge of terminology <3 8, A. 3 Ability to carry out algorithms g , o 8.1 Knowledge of concepts 8 B. 2 Knowledge of principles, rules, '53 and generalizations o E B. 3 Knowledge of mathematical structure a5 1% B. 4 Ability to transform problem elements g E from one mode to another i: 8 B. 5 Ability to follow a line of reasoning E B. 6 Ability to read and interpret a problem g g 0.1 Ability to solve routine problems o g C. 2 Ability to make comparisons U :3 C. 3 Ability to analyze data a C. 4 Ability to recognize patterns, <1 isomorphisms, and symmetries D.l Ability to solve nonroutine problems a, D. 2 Ability to discover relationships :3 51; D. 3 Ability to construct proofs d 0.4 Ability to criticize proofs g D. 5 Ability to formulate and validate generalizations g m 3.1 Attitude o 3 g E. 2 Interest . 3 B E. 3 Motivation g m 8 g E. 4 Anxiety 5 E E . 5 Self- concept 3‘. e m a < o g F.l Extrinsic n: g F. 2 Intrinsic 8: F. 3 Operational <: FIGURE. 3. 3 J. W. Wilson's Taxonomy auth C0118 35 LEVEL TYPE OF ITEM 8.1 Given a sequence (function) that does not have a limit, indicate what part of the definition it fails to satisfy. B.l Give an example of a sequence (function) that does not have a limit and include explanation. 8.1 Given a real number, be able to produce a nonconstant sequence (function) whose limit is that real number and include explanation. C.l When working with sequences, find the associated N for a particular 6 . C.1 When working with functions, find the associated 5' for a particular & . C.l Determine limits of sequences using the results of theorems. C.l Determine limits of functions using the results of theorems. D. 3 Prove a given sequence has a particular limit using the definition for limit of a sequence. D. 3 Prove a given function has a limit at a particular value of the independent variable using the definition for limit of a function. FIGURE 3. 4 Classification of Test Items author and Dave Rajala. One type of item on all four tests was scored before considering another type of item. Guidelines for assigning partial credit are given in Figure 3.5. 36 Type of Item Partial Credit Assignment (see page 28) 1 Right idea, insufficient explanation - 9/11 a. 6/12 for correct example but insufficient reasoning 2, 3 b. No credit if functions and sequences are interchanged 4,5 5/15 for writing‘An - LI 4 e a. Improper use of the quotient theorem: -3 6, 7 b. Max. of 8/15 credit if all reasons are not stated 8,9 8/20 for considering [f(x) - L] ( G or [An-Ll44 FIGURE 3. 5 Guidelines for Assigning Partial Credit Diagnostic Procedures for Treatment A The tests given on the tenth day in Treatment A were used as formative evaluations. After they were graded, a diagnostic form was completed and returned to each student. This provided specific reference regarding the areas in which students needed additional work. A copy of this form is given in Figure 3.6. 37 _r According to the results of your test, you need more work in the following areas: a) b) C) d) e) f) 8) h) i) Sequences that do not have limits Functions that do not have limits How to produce a sequence (function) with a given limit Finding an N ‘ for a given E Finding a S 6 for a given 6 Evaluating limits of sequences using results of theorems Evaluating limits of functions using results of theorems Proving a given sequence has a limit using the definition Proving a given function has a limit using the definition Test results: Problem 1 2 Score t FIGURE 3. 6 Diagnostic Forms for Treatment A Instructional I Alternati‘ ment A after ' was group lec Students . 1}] formative ev: A seconc group sessio 38 Instructional Alternatives: Treatment A Alternative learning strategies were made available to students in Treat- ment A after the formative evaluation was administered. The first of these was group lecture sessions covering material missed by the majority of students. These sessions were held on the first class day following the formative evaluations. A second instructional alternative consisted of three two-hour small group sessions. For these sessions, the chairs in the classroom were separated into four areas as depicted in Figure 3.7. xx xx xx xx xx xx xx D xx xx C xx xx xx xx xx xx xx xx xx xx xx xx xx xx A xx xx B xx xx xx xx xx xx xx FIGURE 3. 7 Room Arrangement for Small Group Sessions Area A contained review material for items of type 1, 2, and 3 (see page 27); area B material for items of type 4 and 5; area C material for items of type 6 and 7; and area D material for items of type 8 and 9. Worksheets (Appendix 39 VII) were provided for each area and students could work in whichever area they chose. The author, Dave Rajala, and students who achieved at the mastery level on the formative evaluation were used as resource persons for these sessions. A record of attendance at all extra sessions in located in Appendix VIII. Summative Evaluation Students in Treatment A received a summative evaluation on the thir- teenth class day following the introduction of the unit on limits. The scores on this evaluation were used as part of the course grade. A copy is contained in Appendix VI . Delayed-Mastery Students One aspect of this study was to identify "delayed-mastery" students in Treatment A. These were students who attained the mastery level (80%) on the second evaluation but who did not attain it on the first one. Figure 3. 8 indicates the number so designated. Analysis of Data The data used to test the cognitive domain hypotheses (see page 6 ) was obtained from tests given in the Calculus I course at CMU during the second semester of the 1973-74 academic year. The first set of data came from the test given during the fifth week of the semester. Subsequent analyses eXE lirr thi: ter Cell met 4O Test Section Mastery Non-mastery 1 8:00 2 24 1 9:00 3 32 2 8:00 17 9 2 9:00 22 13 Delayed mastery: 8:00 15 9:00 19 Total 34 FIGURE 3. 8 Delayed Mastery Students examined both the performance on items referring specifically to the study of limits and the performance on the total test. Copies of parallel forms of this test are available in Appendix IV. The second set of data was the semes- ter averages for the course. A one-way analysis of variance using the six cells indicated in the experimental model of Figure 3.1 was utilized. The method of multiple comparisons was then used to identify differences. Both qualitative and quantitative analyses were conducted in an attempt to determine the effect of the treatments on the affective domain. One quali- tative analysis consisted of interviewing randomly selected (see Appendix X ) students during the last tWO weeks of the Precalculus course. The interviews were conducted by the author and Professor Lakey. Figure 3. 9 indicates the various subgr for intervi ewi l K Gro‘ Nance Mastery 41 various subgroups, their respective sizes, and numbers of students selected for interviewing. Number Group Size Selected Number For Interviewed Interview Early 5 2 2 Nance Mastery Delayed 34 5 5 Nance Non-mastery 21 5 5 Smith Mastery 21 5 3 Smith Non-mastery 40 5 5 Control 152 15 13 FIGURE 3. 9 Number of Students Selected for Interview by Group The fifteen selected from the control group were chosen by selecting three from each of the five sections. A copy of the questions asked during the interviews is available in Appendix XI . A second qualitative analysis was conducted using the results of a questionnaire completed by students in Calculus I at the conclusion of study- ing the section on limits of functions. The responses to this questionnaire were analyzed using a chi square test statistic with several groupings of the cells in the experimental model. A copy of the questionnaire is available in 5pr the 1 lus j A cl. of 5 Cal AC: of ‘ an: 42 Appendix XII. The quantitative analyses for the affective domain consisted of examining the percentage of Fall Semester Precalculus students that enrolled in Calcu- lus I the following semester and the percentage that completed Calculus I. A chi square test statistic was used with four cells and compared the number of students that enrolled in Calculus I to the number that did not enroll in Calculus I. The cells consisted of (1) Treatment A, (2) Treatment B, (3) control group, (4) Precalculus students from the Fall Semester of the Academic Year 1972-73, and (5) Precalculus students from the Fall Semester of the Academic Year 1971-72. A chi square test statistic was also used to analyze enrollment in Precalculus for the cells of the experimental model. CHAPTER III -- FOOTNOTES 1 Bloom, Benjamin S. , et. a1. Handbook on Formative and Summative Evaluation 9_f Student Learning, McGraw-Hill Book Company, New York, 1971, pp. 646—647. 2Block, James H. "Operating Procedures for Mastery Learning", Mastery Learning: Theory and Practice, Edited by J. H. Block, Holt, Rinehart and Winston Inc. , Chicago, 1971, p. 70. 3Smith, William K. Limits and Continuity, The Macmillan Co. , New York, 1974. 4Buchanan, Lexton O. , Jr. Limits: A Transition to Calculus, Houghton Mifflin Company, Boston, 1970. f5O'Brien, Katharine E. Sequences, Houghton Mifflin Company, Boston, 1966. 6Protter, M.H. and C.B. Morrey, Jr. Calculus for College Students, Addison-Wesley Pub. Co., Massachusetts, 1973. 7Lick, Don R. The Advanced Calculus o_f One Variable, App1eton- Century-Crofts, New York, 1971. 8Merrill, M. David, Keith Barton, and Larry E. Wood, "Specific Review in Learning a Hierarchial Imaginary Science", Journal 2f Educational Psychology, 61, 102-109, 1970. 43 11 This chap ing to the toll. and equality c (4) affective ( CHAPTER IV FINDINGS This chapter contains findings of the study. These are reported accord- ing to the following sections: (1) post hoc test for homogeneity of variance and equality of mean, (2) mastery learning, (3) enrollment summaries, (4) affective domain elements, and (S) cognitive domain elements. Post 'Hoc Test A.C.T. scores for students in the nine sections of Precalculus involved in this study were checked for homogeneity of variance and equality of means to see if there were initial differences between sections. The Bartlettl test for homogeneity of variance fell within the acceptable range at the at '-= . 05 level. Subsequent analysis of variance for equality of means produced an F ratio that implied the acceptance of the hypothesis of equality of means between sections. Data used to produce these statistics are contained in Table 4.1. Mastery Learning Treatment A consisted of using a mastery learning approach to teach a section on limits to two of the four treatment sections. An outline is given on page 29 of Chapter III. The effectiveness of mastery learning was deter- mined by an analysis of the formative and summative evaluation results for 44 45 Section Sample Size Mean Standard Deviation Treatment A 12 25. 5 l. 98 Treatment A 14 25. 5 2 . 88 Treatment B 13 25.1 4. 86 Treatment B 15 27.4 3. 29 Control 12 24.1 3. 09 Control 18 25. 6 3. 68 Control 11 26. 5 4. 70 Control 12 27. 4 2. 97 Control 12 26. 9 2. 50 Bartlett test statistif = 13.9 with 8 degrees of freedom Rejection value: OS(8) = 15. 5 Analysis of Variance Table Source Sum of Squares DF Mean Square F Ratio Between means 131. 0261 8 16. 3777 1. 3784 Within 1306. 9448 110 11. 8813 Total 1437. 9664 118 Rejection value: F OS(8,100) = 2.97 TABLE 4.1 Analysis of A.C.T. Scores: Post Hoc Test the four treatment sections of Treatment A and Treatment B. Treatment A formative evaluation item responses are given in Tables 4. 2 and 4. 3. Analysis of these responses determined the material retaught during the group lecture part of the alternative instructional methods. Both sections in this treatment group produced poor results on items of type two, four, and seven. Consequently, these items were discussed in class the following 46 Item" Type 1 2 3 4 6 7 9 Score 11 pts 12 pts 12 pts 15 pts 15 pts 15 pts 20 pts 0 12 8 l3 5 l7 3 l 2 2 l 3 4 l 4 4 5 l 1 6 5 6 l 7 1 8 2 l 9 1 10 l 2 l l 1 1 ll 18 2 12 7 9 2 7 l 13 4 l 1 l4 2 15 l 6 l 1 l6 1 17 4 18 1 l9 6 20 3 Average performance 87% 38% 55% 31% 64% 17% 66% on item *This refers to the instructional objectives on page 28 of Chapter 111. TABLE 4. 2 Formative Evaluation Item Results Treatment A -- Test Form C henl ii Score 47 Formative Evaluation Item Results Treatment A -- Test Form D Item Type 1 2 3 4 6 7 9 Score 11 pts 12 pts 12 pts 15 pts 15 pts 15 pts 20 pt—sA 0 22 7 14 ll 25 3 l 2 1 l 2 3 1 1 4 4 l 1 5 l 3 1 l l 6 l 3 8 2 7 l 8 4 l 1 9 3 2 l 10 4 l l 11 22 12 7 17 l 7 2 13 5 6 l 14 6 3 15 l 4 3 3 l6 4 17 l 18 l 19 9 20 8 Average performance 91% 30% 65% 41% 55% 15% 74% on item TABLE 4. 3 day. Table 4.4 contains scores obtained by students on the formative evalua- tion in Treatment A. Early Mastery Nonmastery Scores Scores 87 78 72 66 62 59 55 50 43 38 27 24 83 77 71 64 60 58 54 49 41 37 27 23 82 77 71 64 60 57 54 48 40 32 26 11 81 75 71 64 60 57 51 46 40 31 26 11 80 73 70 63 60 56 50 45 39 28 25 4 Mean = 52.2 Standard Deviation = 20.1361 TABLE 4.4 Formative Evaluation Scores: Treatment A These scores were recorded for the purpose of identifying early-mastery students. The formative evaluation for students in Treatment A was followed by alternative learning procedures as indicated in Chapter III. A summative evaluation was administered at the conclusion of these procedures. Item responses and scores for this evaluation are contained in Tables 4.5 and 4. 6. Thirty-nine students attained the mastery level, five of whom had been identified as early mastery by the formative evaluation. 49 Item Type 1 2 3 5 6 7 8 Score 11 pts 12 pts 12 pts 15 pts 15 pts 15 pts 20 pts 0 4 ll 1 1 4 1 1 2 3 6 l l 2 4 l 5 1 6 l 6 4 3 2 7 1 8 6 3 2 9 9 13 l 3 10 l 3 l 10 10 ll 27 1 2 l 12 49 38 2 8 7 2 13 13 7 2 14 1 l 15 39 37 18 11 16 17 18 6 l9 2 20 26 Average performance 81% 89% 77% 91% 90% 68% 81% on item TABLE 4. 5 Summative Evaluation Item Results Treatment A 50 Mastery Scores Nonmastery Scores 99 98 94 92 88 87 83 81 79 75 70 65 98 97 93 90 88 86 83 81 77 75 70 65 98 96 93 89 88 86 83 80 76 74 68 61 98 95 92 89 88 86 82 80 76 73 65 55 98 95 92 88 88 84 82 76 72 65 44 Mean = 82.5 Standard Deviation = 11.8937 TABLE 4.6 Summative Evaluation Scores: Treatment A The summative evaluation for students in Treatment B was given the same day the formative evaluation was given in Treatment A. Item re- sponses and scores on this evaluation are given in Tables 4. 7, 4. 8 and 4. 9. Summary: Thirty nine of the sixty students (65%) in Treatment A attained the mastery level while twenty one of sixty-one students (34%) in Treatment B attained that level. The average score on the summative evaluation in Treatment A was 82. 5 compared to an average score of 63. 9 in Treatment B. 51 Summative Evaluation Item Results Treatment B -- Test Form A Item 9 Type 1 2 3 4 6 7 Score 11 pts 12 pts 12 pts 15 pts 15 pts 15 pts 20 pts 0 2 5 7 8 9 23 3 l 2 3 3 4 4 5 l l 2 6 4 4 1 7 l 8 3 9 4 2 l l 10 2 l 2 l 11 22 l 12 19 22 3 8 4 13 2 14 l 15 11 ll 5 16 17 18 19 20 20 g Average performance 86% 76% 75% 59% 58% 23% 69% on item TABLE 4.7 52 Item Type Score 11 pts 12 pts 12 pts 15 pts 15 pts 15 pts 20 pts \OCDNO‘Uer-OONt—Io 10 ll 12 13 14 15 l6 17 18 19 20 t—INh-IN 00 O\ 14 l 5 widths—lid 18 2 26 Average performance on item 77% 78% 65% 58% 68% 30% 93% TABLE 4. 8 Summative Evaluation Item Results Treatment B -- Test Form B 53 Mastery Scores Nonmastery Scores 100 98 85 84 79 70 67 60 54 45 40 34 100 94 85 83 78 70 67 59 48 44 40 28 100 92 85 80 77 70 65 55 47 44 39 27 100 88 85 80 76 69 64 55 47 43 38 22 100 85 85 80 74 68 61 54 46 40 38 19 80 Mean = 65.4 Standard Deviation = 22.1505 TABLE 4.9 Summative Evaluation Scores: Treatment B I'he analyses in the remainder of this report involved grouping cells of the experimental model. Groupings used include the following". (1) Treatment -- Nance Early Mastery (NEM), Nance Delayed Mastery (NDM), Nance Nonmastery (NNM), Smith Mastery (SM), Smith Nonmastery (SNM) (2) Mastery -- NEM, NDM, and SM (3) Nonmastery -- NNM and SNM (4) Treatment A -- NEM, NDM, and NNM (5) Treatment B -- SM and SNM (6) Delayed mastery -- NDM (7) Other mastery -- NEM and SM 54 Test statistics and other results were then analyzed for the following comparisons: (1) Treatment versus Control (2) Mastery versus Nonmastery versus Control (3) Treatment A versus Treatment B versus Control (4) Delayed mastery versus Other mastery versus Nonmastery versus Control (5) All six cells of the experimental model Enrollment Enrollment figures were examined to see if the treatment had an effect on the number of students taking Calculus 1. Analysis of these figures was accomplished by considering Precalculus and Calculus I enrollments for three years. All fall semester Precalculus and winter semester Calculus 1 sections were used for the Academic Years 1971-72 and 1972-73. Enrollment figures obtained from these years were compared with figures obtained from the nine Precalculus sections involved in the experiment. Table 4.10 contains this information. Data from Table 4.10 were analyzed by using the chi square test sta- tistic and a test for proportion. Six groupings were considered. The chi square statistic was used to test the null hypothesis of independence between classifications at thefi = .05 level of significance for five of these six groupings. The other grouping, Treatment versus Control, was tested with 55 Number Number of students of students Percent Semester Group completing enrolling in enrolled in Precalculus Calculus I Calculus I Fall 1971 All sections 438 173 39 Fall 1972 All sections 363 169 47 Fall 1973 NEM 5 5 100 Fall 1973 NDM 34 13 38 Fall 1973 NNM 21 8 38 Fall 1973 SM 21 13 62 Fall 1973 SNM 40 15 38 Fall 1973 Control 152 85 56 Fall 1973 Treatment A 60 26 43 Fall 1973 Treatment B 61 28 46 Fall 1973 Mastery 60 31 52 Fall 1973 Nonmastery 62 23 38 Fall 1973 Other mastery 26 I8 69 Fall 1973 Treatment 121 54 45 TABLE 4.10 Enrollment Summaries a 2 test statistic for equality of proportion with the alternative hypothesis of proportion of Treatment students enrolled in Calculus I is not equal to the proportion of Control students enrolled in Calculus I. A summary of these tests and conclusions is contained in Table 4.11. Three of the group- ings produced chi square values that implied the rejection of the hypothesis of independence between grouping and enrollment. Cell components of the value of the test statistic that produced the rejections are located in Appendix XV . 56 333m 393.22 “35:05am ax. mqmdfi. a- H An.— ”0: bounce no: on 3; N 84 n N 35:60 £55on9 mfimofioacf . 33:00 :5: 65 bouncy— w.\. u A28 KI 5.2 n «K. .cfioumdnnsz .cfioumafi N H050 5.5»de paragon E35093 as: we 3.950 05 ~00an “on on oofi .i. Amy mX- aim n «K. .Eumafieoz .cfloummE assesses :2 mo . 8880 05 83.3 go: on 3d u Amy «K m.m u «is m unusuaouh .4 80533. 335093 . 0 .22m .35 :3 cesium r: u enough 1: u NX. .222 .202 .352 235093 . ugguoufi who“ . mo . :8 cascade a a u 5 «x. can u mi. 38ch «R: .22 .RE 03: 03.? 833080 eonooflom sunbeam game. 33:80 Summary: | Control group students from i on enrollment \ lhis analysis Ill e111'011edin Calt mastery and No The 2 test between the Tre was not Sufficiel two'sided test a “Quite an * 1e last was used in ment effect Won tation of the ins however, that e Therefore: rail test was used. if a one‘tailed I % study withdrew these were in t1 57 Summary: The statistics of Appendix XV indicate that the Fall 1973 Control group had significantly more students enroll in Calculus I than did students from the previous two years. Consequently, the treatment effect on enrollment was determined by considering groupings within the year 1973. This analysis indicated that more Other mastery students than expected enrolled in Calculus I while enrollment was less than expected for Delayed mastery and Nonmastery students. The Z test statistic was used to test equality of enrollment proportion between the Treatment group and the Control group. The Z value of 1. 86 was not sufficient to reject the hypothesis of equality of proportion for a two-sided test at the A = .05 level. For the produced Z value, it would require an at level of . 0628 to reject the null hypothesis. The two-tailed test was used in this case because the original hypothesis was that the treat- ment effect would increase enrollment. Student comments during the presen- tation of the instructional unit in the Treatment group made it apparent, however, that enrollment might decrease as a result of the treatment. Therefore, rather than reverse the inequality of the hypothesis, a two-tailed test was used. A statistically significant difference would have been produced if a one-tailed test had been used with the proportions interchanged from the original conjecture. Withdrawals from Calculus 1: Nine of the 139 students involved in this study withdrew from Calculus 1 before the end of the semester. Two of these were in the Nance nomnastery group, one in the Smith nonmastery group, and s: ment did not Affective Dc determined the Precalc the intervi. appronma. invesu‘ gate of alum'ltBtie toward the given in T Figure 4.: The i of Each in <1)E m (2) \ 58 group, and six in the Control group. These results indicate that the treat- ment did not have an effect of the number of withdrawals from Calculus I. Affective Domain Interviews: Part of the treatment effect on the affective domain was determined by analyzing responses obtained from interviewing students in the Precalculus sections. A discussion of the selection of these students and the interview procedures is given in Chapter III. The interviews required approximately ten minutes apiece to conduct and were primarily used to investigate two elements in the affective domain: (1) the existence or lack of anxieties regarding the first semester calculus course, and (2) attitude toward the first semester calculus course. Results of the interviews are given in Table 4.12 and a summary of these responses are contained in Figure 4.1. The interviewers responded to the following two items at the completion of each interview: (1) Briefly discuss your conception of student anxieties or lack of anxieties regarding Calculus 1. (2) What is your opinion of the student's attitude toward Calculus I? Summaries of responses to these items are contained in Figure 4. 2. 59 momeamom BoEouE N3. mafia. e N a a e e o a a o N N tunes 3:5 a N a N a. N N N N o N N Naccscdacz e a N a N a a a N e c N E382 a N_ a N c a a c S o N 2 successes N N N a. N N a a. N o N N N accesses... N N. N N a N N N N e c N < accessed. N N c a o 0 addresses 8e e N N chase N N a N N N a N _ o a N 22m o N a N e e e a N e a N 5 N a e a N a N N a o a o 222 o a N o N a a e a e N N 292 e N o N e o o o N o N N 52 < <4 m r :2 z :z a :2 32 4... 3385 3 Na N32: N N sue L Item I Seven Eight Nine 60 Item Summary of Responses Six Seven Ei ght Nine Ten, Eleven, and Twelve Thirteen Fourteen One of thirteen Control group students thought he was doing below average while six of twenty Treatment group students thought they were doing below average. Ten of twelve students in Treatment A indicated a lack of positive attitudes regarding the Precalculus course, while twelve of twenty-one students in Treatment B and the Control group had positive attitudes. Eight of thirteen students in the Control group thought Precalculus was harder than they expected compared to seven of twenty in the Treatment group. Eight of ten students who achieved mastery in either treatment group exhibited positive attitudes towards the unit on limits, while only two out of ten students in the nonmastery group favored the unit. Four students in the treatment sections changed their minds about taking Calculus 1. Of these four changes, one decided not to take calculus because of a curricu- lum change, one decided to take calculus because of an advisor's recommendation, and two decided against calculus because of their unsatisfactory performance in Precalculus. None of the thirteen interviewed in the Control group changed their minds regarding calculus. Thirteen out of seventeen students from the treatment sections thought Calculus I would be harder than other math courses they had taken, while only one out of ten in the Control group had the same reaction. All Delayed-mastery students interviewed from Treat- ment A expect to achieve at an above average (A or B) level in calculus. FIGURE 4.1 Summary of Interview Responses Group NEM NDM MN SM sun Comm 61 NDM NNM SM SNM Control w» , forward to it. They did not Object to the section on limits, These students thought Calculus I would be more difficult than Precalculus, but they were not overly concerned. They recognized the sequence as the natural order and had healthy, positive attitudes. Students interviewed in this category ex- pected to receive A's or B's in calculus and did not exhibit anxiety. These students expressed appreciation for the mastery learn- ing approach. Positive attitudes and lack Of anxieties con- cerning Calculus I characterized this group. They expected calculus to be more difficult than previous mathematics courses, but they thought they could do at least B level work. The students interviewed thought Calculus I would be very difficult. TWO Of the five said they were "afraid" Of calculus. There were negative attitudes toward Calculus I and the section on limits in Precalculus. These students had attitudes and reactions similar to those Of the Nance early-mastery group. Their attitudes were positive and they did not exhibit anxiety toward Calculus I. These students exhibited a negative attitude concerning Calculus I. They think it will be hard and are not looking however, because they thought it would help them. The students interviewed in this group had positive attitudes and no anxieties about taking Calculus 1. Nine Of the ten responses indicated that it would not be a very difficult course. FIGURE 4. 2- Analysis of Anxieties and Attitudes Toward Calculus I Questionnaire: Treatment effect on the affective domain was partially analyzed by examining the results Of a questionnaire completed by Calculus I students during the Winter Semester 1974 (Appendix XII). All but eight Of the 62 one-hundred thirty-nine students involved responded tO the questionnaire. Table 4.13 contains tables formed by considering the responses Of each cell in the experimental model to the five questions. The cell sizes Of these tables were insufficient to produce statistically valid results when six groups were crossed with five responses per question. Consequently, responses and cells Of the experimental model were grouped to produce larger cell sizes. The most refined grouping which produced this was a three-level response scale rather than a five-level scale. This was accomplished by combining responses "a" and "b" and responses "d" and "e". The groupings of the cells Of the experimental model were those indicated On page 53. Table 4.14 contains results produced by these groupings. A chi square test was used to analyze the results and significance was tested at the at = . 05 level. The chi square values on twelve Of the twenty questions reported in Table 4.14 indicate a rejection Of the hypothesis Of independence between groups and responses. An analysis Of the values contributing to these rejection figures is reported in Appendix XIV. A summary Of these results is contained in Figure 4. 3. ngnitive Domain Test on limits: A test covering limits was administered to the Calculus I students during the fifth week Of the Winter Semester 1974. Five forms (A, B, C, D, E) of the test were used. Items 2, 3, and 4 were parallel on all forms while Item 1 was parallel on forms A, B, and C. The test forms 1 00000 0.1000 10 0 10 00000 11 24.477 629 33 0 38268 30 37 Group NEM NDM SNM Control Group NEM NDM NNM SM SNM Control SM 63 4 4 ll 34 25 13 a 0 3 5 a 10 51 Group NEM NDM SM SNM Control Group NEM NDM SM SNM Control Group NEM NDM 04. 31 05 NNM SM TABLE 4.13 6 Questionnaire Responses 5 245 21 Control SNM 64 Degrees Chi Square Chi Square Grouping of Critical Value Freedom Value by Question TreatmentA Q1 -- 6.02 Q 2 -- 15.44 X TreatmentB 4 9.4 Q3 -- 4.30 Q4 -- 7.44 Control Q5 -- 15.92 X Q1 -- 5.78 Treatment 2 5.99 Q2 -- 13.87 X Q3 -- 3.25 Control Q4 -- 6.97 X Q5 -- 10.28 X Mastery Q1 -- 10.57 X Q 2 -- 16.61“ X Nonmastery 4 9.4 Q3 -- 4.43 Q4 -- 8.81* Control Q5 -- 11.58 X Delayed mastery Ql -- 17.57* X Other mastery 6 12.59 Q2 -- 21.72“ X Q3 -- 12.62* X Nonmastery Q 4 -- 8.82* Q5 -- 18.53 X Control *Fewer than 80% of the cells had five or more responses. X -- Reject the null hypothesis of independence. TABLE 4.14 Questionnaire Data 65 3353 0505500 3 555m m .0 0330a .350Bm 3.555502 05 03 55 555553 53 335 3 >005 05 0503 3503a F5532 m 35:00 .3525 3.555502 05 03 55 535 53030 0503 550:5 F5552 n 3555502 .5555 55 505: 53 5303003 03.505 35030 3555502 _ F5552 .355 53003 5:3 55555.3 000505 3550553 5035 55555 0.5. m .3550 503 505 05 55 500: 0.58 .5 535m 030:5 350:5 5555.5. .533 3050955 v .Fnowuumo 05m 05 5 0.55 3550553 05 3503a 3550 05:3 F5550 3550 :505: 05 5 55055 .533 3550353 05 35005 505 5555.3. N 5555.5. .Faowouao :55 5553 53.. 05 5 55055 533 05 350:5 m 5555.3. 333 F5550 :555553: 05 5 55055 533 05 35005 < 5555.5. m 3.350 _ 530095 55 m “5553. 505: 53 m 53030 3505 350Bm 4 5555.5. 533 355058 N < “555.5. .5355 .550 55 .555 35005 F5555 -52 0» 5:53 0.53 503 m5 :0 55055 .3595 F5555 00530 n .3525 >553: .550 05 05 55 530050 0.55 335: .3 >035 05 053 35005 F5555 00530 m 630005 55 .535 53030 053 35005 F5555 550 3.23 35000 0305 5 530030 5 305 an 00 53030 053 3500.3 F5055 00530 N 3555502 .0355 55 .505: 5303005 F5555 550 05.3 350:5 F5555 00530 .3595 5558 550 3 005950 a 5555 0053a 3353 53500 53:80 66 differed only in that A, B, and C had a proof about limit of a function, whereas forms D and E had a proof about derivative of a function. Other items on the tests did not involve limits (see Appendix IX). Item and test scores are given in Appendix XVI. Scores on Item I (twenty points possible) of forms A, B, and C were such that analysis of variance was not possible on the group means because the Bartlett test statistic for this item had a value of 28.1 while the critical value at the“ = .05 level of significance was 9.5. Responses were subsequently categorized into two levels: (1) those with scores less than eighteen, and (2) those with scores of eighteen, nineteen, and twenty. The number of responses in these categories by groupings of cells of the experimental model are given in Table 4.15. Grouping l Score Mean I 0-17 1 18-20 J NEM 0 I 20. 0 NDM l 8 18. 8 NNM . 2 3 15. 0 SM 0 6 l9. 7 SNM 0 6 l9. 7 Control 5 38 18. 9 Treatment A 3 12 17.6 Treatment B 0 12 19. 7 Mastery I 15 19. 2 Nonmastery 2 9 17.6 Other mastery 0 7 l9. 7 Treatment 3 24 18. 5 TABLE 4.15 Calculus I Test Item I -- Forms A, B, and C 67 Scores on Item 2 for all five forms of the calculus test also produced group means that did not permit analysis of variance. The Bartlett test statistic for this item was 14. 2 while the critical value was 11.07. As before, the responses were categorized and reported by various groupings. This information is contained in Table 4.16. Grouping Score Mean -17 I - NEM 1 4 l9. 0 NDM 3 10 18. 2 NNM 5 2 15. 6 SM 2 11 19. 3 SNM 4 10 18. 0 Control 28 52 17. 2 Treatment A 9 l6 l7. 6 Treatment B 6 21 18.6 Mastery 6 26 18. 8 Nonmastery 9 12 17. 2 Other mastery 3 15 19. 2 Treatment 15 37 18. 5 A TABLE 4.16 Calculus I Test Item 2 -- Forms A, B,C,D,E Each of the five test forms had three parallel items involving limits. Question two involved finding the limit of a quotient of functions with reasons given for each step. Questions three and four required students to produce examples of functions which met certain conditions and to include reasoning. The total possible points for these three items was thirty three. Analysis of these items was achieved by dividing the total scores into two categories and using a chi square test statistic. The categories were (1) scores from zero 68 through twenty nine, and (2) scores from thirty through thirty three. Table 4.17 contains the responses by category and Table 4.18 contains results obtained from analyzing these scores. Grouping L Score I Mean | 0-29 T 30-33 1 NEM 2 3 30.0 NDM 5 8 28. 5 NNM 6 1 24.9 SM 3 10 31.0 SNM 6 8 28.6 Control 48 32 27. 2 Treatment A 13 12 27. 8 Treatment B 9 18 29. 8 Mastery 10 21 29. 8 Nonmastery 12 9 27. 4 Other mastery 5 13 30.7 Treatment 22 30 28. 8 TABLE 4.17 Responses by Cells to Limit Items 2, 3, and 4 of the Calculus I Test Degrees of Chi square Chi square Grouping freedom test statistic critical value OR = .05 NEM, NDM, NNM, SM, SNM, C 5 11.30 11.07 Treatment-Control 1 3. 96 3. 84 Mastery- Nonmastery-Control 2 0 5. 99 Delayed mastery-Other mastery- 3 7 3 7 8 Nonmastery- Control ° ' Treatment A-Treatment B- 2 7. 2 5. 99 Control TABLE 4.18 Analysis of Student Performance on Limit Items in Calculus I Test 69 Chi square contingency tables for grouping of cells of the experimental model are contained in Appendix XVII. The data of Table 4.18 indicate that the Treatment group performed significantly better than the control group on the limit items. Further exa- mination of this data and the material in Appendix XVII indicate that most of the achievement difference was due to students in Treatment B. Treatment A students performed as expected while fewer Treatment B students than expected scored low (below thirty) and more than expected scored high (thirty and above). The last analysis made from data obtained from the Calculus I test was an examination of total scores. Means for groupings of cells of the experi- mental model are given in Table 4.19. Grouping Size l Mean 1 Standard Deviation NEM 5 91. 4 5. 9 NDM 13 83. 4 14.1 NNM 7 67. 4 13.1 SM 13 91. 8 6. 3 SNM 14 81. 4 l4. 2 Control 80 83. 0 14. 5 Treatment A 25 80. 5 14. 3 Treatment B 27 86. 4 ll. 9 Mastery 31 88. 2 10. 6 Nonmastery 21 76. 7 14. 7 Other mastery 18 91.7 5.9 Treatment 52 83. 6 l3. 7 TABLE 4.19 Group Means and Standard Deviations for Calculus I Test Scores 70 The Bartlett test statistic for homogeneity of variance of this data is 12. 7 while 1205(5) = 11. 07. However, the F ratio for an analysis of variance of these means is 3. 33 and €056,120) = 2. 29. Consequently, one can be reasonably sure that the analysis of variance result is statistically signifi- cant. The analysis of variance table in Table 4. 20 indicates a rejection of the hypothesis of equality of means. Source Sum of Degrees of Mean F Squares Freedom Square Ratio Between means 3081. 8 S 616. 4 3. 3 Within 23324. 4 126 185.1 Total 26406. 2 131 TABLE 4. 20 One-Way Analysis of Variance for Calculus 1 Test Scores Due to unequal sample sizes, a Scheffe2 multiple comparison test was used to identify differences between means. Table 4. 21 contains the results of these comparisons. The null hypothesis of equality of means was rejected only for the comparisons of Nonmastery versus Mastery and Nonmastery versus Other mastery. All other comparisons, in particular Treatment versus Control, do n_ot reject the hypothesis of equality of means. Semester average in Calculus I: The second analysis of the treatment effect on the c0gnitive domain was conducted by examining students' semester averages in Calculus I (Appendix XVI). The average for each student was obtained by equally weighted percentage scores from the following three 71 A Comparison Confidence Interval Conclusion" Treatment A - Treatment B - 19. 2 —_ 7. 5 Do not reject Treatment A - Control - 13. 5 __ 8. 9 Do not reject Treatment B - Control - 6.7 — 13. 8 Do not reject Mastery - Nonmastery .4 —— 28.5 Reject Mastery - Control - 4.7 —- 16.3 Do not reject Nonmastery - Control —20.5 —- 3. 2 Do not reject Delayed mastery - Other mastery -25. 8 —— 9. 4 Do not reject Delayed mastery - Nonmastery - 7.6 —- 25.6 Do not reject Delayed mastery - Control - 13.4 —— 14.1 Do not reject Other mastery - Nonmastery 1.0 — 33.3 Reject Other mastery - Control - 4.6 -— 21.7 Do not reject Treatment - Control - 8.6 —— 8.6 Do not reject *Rejection of the null hypothesis of equality of means occurs when the confidence interval does not include zero. TABLE 4. 21 Scheffe Multiple Comparison Test for Equality of Means Calculus I Test sources: (1) ten quizzes, (2) three one-hour examinations, and (3) a final examination. Averages for groupings of cells of the experimental model are given in Table 4. 22. Means were analyzed by a one-way analysis of variance. The Bartlett test statistic was 11.15 while the rejection value was X2055) = 11.07. However, the F ratio for analysis of variance was 5. 57 compared to E05(5,120) = 2. 29. As before, this allows us to reject the null hypothesis of equality of means between cells. The analysis of variance table is given in Table 4. 23. Results of the Scheffe multiple comparison test are contained in Table 4. 24. The only comparisons that produced a statistically significant difference of means were those that involved the 72 Grouping I Size l Mean I Standard Deviation NEM 5 85. 0 ll. 0 NDM 13 71. 9 l7. 3 NNM 6 58. 0 17. 4 SM 13 80. 0 12. 4 SNM 14 74.1 9. 6 Control 79 79. 9 9. 9 Treatment A 24 71. 2 l7. 8 Treatment B 27 76.9 11.0 Mastery 31 77 . 4 l4. 7 Nonmastery 20 69. 3 13. 8 Other mastery 18 81. 4 ll. 6 Treatment 51 74. 0 l4. 9 TABLE 4.22 Semester Averages by Groupings of Cells of the Experimental Model Sum of Degrees of Mean F Source Squares Freedom Square Ratio Between means 3652 5 730. 4 5. 57 Within 16268 124 131. 2 Total 19920 129 TABLE 4. 23 Analysis of Variance Table for Semester Averages by Cell 73 Comparison Confidence Interval Conclusion“ Treatment A - Treatment B -16. 8 6. 0 Do not reject Treatment A - Control - 17. 9 1. 4 Do not reject Treatment B - Control - 11. 5 5. 8 Do not reject Mastery - Nonmastery .7 25.1 Reject Mastery - Control - 9. 8 7.9 Do not reject Nonmastery - Control - 24. 2 3. 4 Reject Delayed mastery - Other mastery —25. 4 4. 2 Do not reject Delayed mastery - Nonmastery - 8. 5 20. 2 Do not reject Delayed mastery - Control - 19. 6 3. 6 Do not reject Other mastery - Nonmastery 2. 5 30. 3 Reject Other mastery - Control - 8. 5 l3. 7 Do not reject Treatment - Control - 13. 5 l. 3 Do not reject *Rejection of the null hypothesis of equality of means occurs when the confidence interval does not include zero. TABLE 4. 24 Scheffe Multiple Comparison Test for Equality of Means Total Percentage Grade for Calculus I Nonmastery students. Summary: Two implications arise from the data of Table 4. 22 and 4. 24. The first is that the average score for Delayed mastery students (71. 9) is much closer to that for Nonmastery students (69. 3) than it is to that for Other mastery students (81. 4). Although the difference between Delayed mastery and Other mastery is not statistically significant, it is an indication that Delayed mastery students tend to perform more like Nonmastery students than Other mastery. The second implication is that the Treatment students scored 5. 9 percentage points lower than the Control students. This is not statistically 74 significant, but it suggests further investigation into the feasibility of taking time from the Precalculus course to introduce special topics. FOOTNOTES -- CHAPTER IV 1 Dixon, Wilfrid]. and Frank J. Massey, Jr. Introduction to Statis— tical Analysis. McGraw Hill, New York, 1969, p. 308. 71mm, p. 167. 75 CHAPTER V CONCLUSIONS AND IMPLICATIONS Included in this chapter are (l) a summary of the procedures of the study, (2) findings of the study, (3) conclusions based upon analysis of the data, (4) a discussion of selected components of the study, and (5) implica- tions for further research. SummarLof Procedures This study investigated the effects of teaching a unit on limits to pre- ' calculus students at Central Michigan University. Nine sections of approxi- mately thirty students each constituted the population. Two sections received Treatment A, two received Treatment B, and five were used for a Control group. Treatment A consisted of using a mastery learning strategy to teach the unit; Treatment B consisted of presenting the same unit in a regular“ classroom situation; and sections in the Control group received no instruc- tion regarding limits. The mastery learning strategy used in Treatment A consisted of (l) for- mulating instructional objectives, (2) presenting the unit of instruction, (3) administering a formative evaluation, (4) providing each student with cfiagnostic results, (5) using alternative instructional procedures, and *"Regular" means no special strategy or technique was used. The instructor taught the way he normally would present any other material. This consisted mainly of lecturing and answering questions. 76 77 (6) administering a summative evaluation. Students who achieved at or above the mastery level (80%) on the summative evaluation but not on the formative evaluation were identified as "delayed-mastery" while those who attained that level on the formative evaluation were identified as "early-mastery . Treatment effects on the affective domain elements were determined in two ways. One was by interviewing randomly selected students from the Precalculus sections. The other was by analyzing responses to a question- naire completed by Treatment and Control students enrolled in Calculus I. In addition to these analyses, enrollment figures in Precalculus and Calculus I for the years 1971, 1972, and 1973 were examined to see if the Treatment affected the percentage of Precalculus students enrolling in Calculus I. The effect of the treatment on achievement in Calculus I was analyzed at two stages of the course. Data from the test covering limits was used first. Student performance was measured on (1) the questions involving limits and (2) the total test scores. The semester percentage for each student provided the second set of data. For the purpose of these analyses, students in Treat- ment A were identified as Nance early mastery, Nance delayed mastery, or Nance nonmastery; and students in Treatment B were identified as Smith mastery or Smith nonmastery. Results The results of this study will be reported according to the organization implied in Chapters III and IV. First the mastery learning results will be 78 given and then the treatment effects regarding Calculus I will be divided into enrollment, affective domain, and cognitive domain results. Mastery Learning: The null hypothesis of H0: the proportion of students achieving mastery in Treatment A (P A) equals the proportion of students achieving mastery in Treatment B (P8) was tested using a Z test statistic with a significance level of o( = .05. The alternative hypothesis was Ha: P A) PB. Thirty nine of sixty Treatment A students achieved mastery compared to twenty one of sixty one in Treatment B. The Z test statistic for these proportions is Z = 3. 33 where the null hypothesis is rejected for values of Z > 1.645 whendk = . 05. Therefore, the alternative hypothesis of P A) PB was accepted. Enrollment: (A) The null hypothesis of H : the proportion of Treatment 0 group students (PT) enrolling in Calculus I equals the proportion of Control group students (PC) enrolling in Calculus I was tested using a Z test statistic with a significance level of UK= . 05. The alternative hypothesis was H a: PT ¥ PC Sixty students in Treatment A, sixty one in Treatment B, and 152 in the Control group completed Precalculus. Of these students, twenty six, twenty eight, and eighty five respectively enrolled in Calculus I. This produced percentage enrollment figures of fifty-six percent for the Control group and forty-five percent for the Treatment group. The Z value was 1. 86 where the rejection value at the ds = . 05 level for a two-sided test was I. 96. Therefore, the null hypothesis of equality of proportions between Treatment and Control 79 groups was accepted. (Comment: The hypothesis concerning enrollments was that enrollment percentage would be increased as a result of the treat- ment. The computed enrollments, however, indicated that eleven percent EVE. students enrolled in Calculus I from the Treatment group. Conse- quently, a two-sided test was used with the alternative hypothesis Ha: PT 7‘ P C rather than a one-sided test with the alternative hypothesis Ha: PT) PC . If the hypothesis had been that the treatment would decrease enrollment, then a one-sided test with alternative hypothesis Ha: PT< PC would have pro- duced a statistically significant difference in enrollment.) (B) The percentage of students remaining in Calculus I was also not affected by the treatment. Fifty one of fifty four (94%) Treatment group students completed Calculus I compared to seventy nine of eighty five (93%) from the Control group. The Z test statistic for equality of proportions between these groups is Z = -. 25 where the rejection value for 0k = . 05 is Z ) 1.645. Affective Domain: Treatment effect on the affective domain was analyzed by considering student responses to interviews and a questionnaire. The hypothesis as stated in Chapter I is: a unit on limits in Precalculus will improve attitudes (1) prior to taking Calculus I and (2) during Calculus I. The findings with respect to this hypothesis are reported below. (A) Interviews conducted at the end of the Precalculus course indicated the following results: 1. Treatment group students thought they were doing poorly in 80 Precalculus. 2. Treatment group students thought Calculus I would be very diffi- cult as opposed to Control group students who thought it would not be harder than other courses. 3. The treatment effect caused negative attitudes and anxieties toward Calculus I for the Nonmastery students. Otherwise, Mastery and Control students had positive attitudes and no apparent anxieties toward calculus. (B) Questionnaire responses obtained during the third week of the Calculus 1 course are given in Chapter IV. These responses were analyzed using a chi square test statistic for each question on the questionnaire. Significance was tested at the ok= .05 level. The following two results of this analysis deserve special mention. 1. Significantly more than expected Control group students thought Calculus I was "harder than expected" compared to significantly fewer than expected Treatment group students who responded to the same item. 2. Treatment group students experienced significantly less frustra- tion when studying limits than did the Control students. gignitive Domain: Treatment effect on achievement was examined by considering the Calculus I test covering limits and the final percentage score for Calculus 1. Analysis of scores on the calculus test covering limits was accomplished by using a null hypothesis of H : there is no significant 0 81 difference in achievement for cells of the experimental model. This was tested by using a one-way analysis of variance. When the items covering limits were tested, the Bartlett test statistic of 20.7 was too high to permit use of analysis of variance. Consequently, scores were categorized and a chi square test statistic was used. There was a significant difference at the $= . 05 level between the achievement of Treatment and Control students. Subsequent analysis of the chi square partial values indicated that the Treatment group students performed better than expected. Analysis of the total test scores also used the null hypothesis of H0: there is no significant difference in achievement for cells of the experimental model. In this case, the Bartlett test statistic was within the acceptable range and a one-way analysis of variance produced an F test statistic of F = 3. 3 where the rejection value was F05(5,120) = 2. 29. Consequently, the null hypothesis of equality of means was rejected. Subsequent multiple comparisons were made using a Scheffe test and indicated that the only statistically significant differences were between (1) the Nonmastery and Mastery groups and (2) the Nonmastery and Other mastery groups. Semester averages in Calculus I were also analyzed based on the null hypothesis H0: there is no significant difference in achievement for cells of the experimental model. A one-way analysis of variance“ produced an F test statistic of F = 5. 57 where the rejection value was F05(5,120) = 2. 29. *The Bartlett test statistic for homogeneity of variance was 11.15 while the rejection value was 2 (5) = 11.07. However, the F ratio was large 0 enough to reject the null gypothesis and perform multiple comparisons. 82 Multiple comparisons then produced statistically significant differences be- tween the following. (1) Mastery and Nonmastery, ( 2) Nomnastery and Control, and (3) Nonmastery and Other mastery. All other comparisons produced no significant difference. Delayed Mastery: A unique aspect of this study was the identification of delayed mastery students in Treatment A. An analysis of their subsequent behavior was obtained by constructing a profile of this group compared to other cells of the experimental model. This information is contained in Figure 5.1. Item Group Most Closely Resembled Interview responses Other mastery Questionnaire responses Smith nonmastery Enrollment in Calculus I Nonmastery First calculus test: (1) limit items (1) Smith nonmastery (2) total score (2) Smith nonmastery Semester percentage in Calculus 1 Smith nomnastery FIGURE 5.1 Profile of Delayed Mastery Students The purpose of this identification and subsequent profile was to examine what carry-over effect the alternative instructional procedures and additional time spent studying limits would have on these students. Figure 5.1 indicates that the Delayed mastery group responses to all evaluation items used during the Calculus I course were similar to those of Nonmastery students in either 83 Treatment A or Treatment B. Consequently, the alternative instruction and extra time seem to have had little carry-over effect on the Delayed mastery students . Conclusions Reject the hypothesis that a mastery learning strategy, employed on a unit of limits of sequences and limits of functions, will result in no significant difference between the proportion of students achieving the mastery level in a mastery learning situation and the proportion of students achieving the mastery level in an expository classroom situation. Do not reject the hypothesis that a unit on limits in Precalculus will not affect attitudes (a) prior to taking Calculus I (h) during Calculus I. Do not reject the hypothesis that there will be no significant differ- ence between the percentage of students enrolling and remaining in Calculus I after having had a unit on limits and the percentage of students from the Control group enrolling and remaining in Calculus I. Do not reject the hypothesis that there will be no significant differ- ence in achievement in Calculus 1 between students in the treatment groups that achieve mastery and those that did not achieve mastery. 84 5. Do not reject the hypothesis that there will be no significant differ- ence in achievement in Calculus 1 between delayed mastery students and other mastery students in the treatment groups. 6. Reject the hypothesis that an introduction to limits prior to calculus will result in no significant difference in achievement on the work with limits in calculus. 7. Do not reject the hypothesis that an introduction to limits prior to calculus will result in no significant difference in achievement in the first semester of calculus. Implications for Education Instructional Unit: Approximately one-half of the time spent studying limits was used for the study of limits of sequences. Since the Calculus I course at Central Michigan University does not cover this topic, the time devoted to this may have been more effectively used in additional study of limits of functions. A second point is that notation was a problem for some of the students. The mathematical phrase n ) N tended to be confusing. Perhaps a change to n ) M would correct this in future work. Mastery Learning: The mastery learning strategy of Treatment A was effective as indicated in the conclusions on page 83. However, several problems occurred which should be considered for future work. First, the time spent for alternative instructional techniques may have produced the same results in an expository situation. Related to the alternative instruction 85 problem is the question of what to do with the early mastery students between the formative and summative evaluations. In this study, they were used as resource people during the small- group alternative instruction sessions. They might not enjoy doing this if an entire course were to be taught via a mastery strategy. A second problem is that the difference between early mastery and delayed mastery students may not be an accurate indication of their abilities. Students in this study were informed that the formative evaluation would not count on their grade and that there would be a summative evaluation several days later. These reasons may have resulted in students being identified as delayed mastery when they could have achieved at the mastery level if only one evaluation were given. Closely related to this problem is that of ' how many evaluations should be given. Would those students who scored between sixty and eighty on one summative evaluation socre above eighty on a subsequent evaluation? How many examinations are required to maximize class progress and still account for individual differences? A third area of concern is that both Treatment A and Treatment B resulted in less time being spent on the topics ordinarily studied in Pre- calculus. Since the semester average in Calculus I of Treatment students was 5.9 percentage points lower than the Control group, this may mean that prior knowledge of limits has less effect on success in Calculus I than the knowledge of other topics in Precalculus. Sources of Variation: Sources of variation affecting the results of this 86 study include the following: 1. Treatment A students spent three more days studying limits than did Treatment B students. Both Treatment A and Treatment B students spent less time studying the other Precalculus topics than did the Control group students. Five different instructors taught the Control sections. Treatment A and Treatment B sections were taught by different instructors. Treatment A sections met at 8:00 a.m. and 9:00 a.m. while Treatment B sections met at noon and 1:00 p.m. Calculus I was taught at two different times: 10:00 a.m. and 2:00 p. m. Students in Calculus I had nine different recitation instructors. Students were not randomly selected for this study. However, a post hoc test of A. C.T. scores indicated that the sections were evenly matched for homogeneity of variance and equality of means .' Other comments: Statistical analyses of affective domain elements are difficult to obtain. In this study, it was not possible to show that the Treat- ment effect changed attitudes toward Calculus I. It was possible, however, to show that a statistically significant percentage of students from the Treat- ment group felt they experienced less frustration when studying limits in Calculus I than did the students from the Control group. The next comment concerns the Calculus I test that produced data for 87 part of the analysis in the cognitive domain. The limit items on these tests had such high averages that analysis of variance was not possible. If these items had been better able to distinguish between ability levels, Treatment effects could have been more thoroughly examined. The last comment has social and economic implications. Although the Calculus I enrollments for Treatment and Control students were not signifi- cantly different ( d~ = . 05), it is true that enrollment of Treatment students was 11% less than that of Control students. If some of the Treatment students did not take Calculus I because the unit on limits made them realize that Calculus was not what they expected, they might have enrolled in Calculus I and then dropped the course had it not been for the unit on limits. These students have thus saved some of their tuition and some time that would have been spent in Calculus I. On the other hand, enrollment figures are of pri- mary importance in these days of careful auditing of student credit hours. Conceivably a mathematics department could suffer economic consequences if the Treatment of this study were extended and the enrollment percentages remained the same. An examination of this problem is suggested as a topic for further research. Suggestions for Further Research Following are listed related questions that deserve further consideration: 1. Do the carry-over effects of a mastery learning strategy differ from the carry-over effects of an expository strategy? This study has 88 shown there was no significant difference in achievement in Calculus I between Delayed mastery and Other mastery students. However, the profile of Figure 5.1 indicates that the Delayed mastery students most closely resemble Nonmastery students when one considers the analyses of this study. Perhaps subsequent research could more carefully define and control parameters relating to Delayed mastery students. Would a greater variety of alternative instructional techniques pro- duce even better results for mastery learning? (Audio-visual tapes, more effective use of the reading list, tutoring, etc.) Would mastery learning be effective if all instructional objectives were tested at the Analysis level of Wilson's taxonomy? In this study, mastery of most items was tested at lower levels of difficulty. Results of the mastery strategy indicate it might be as effective if all items were tested at the highest level of the taxonomy. What effect would a different Treatment (no sequences, no ( e , J ) notation, longer intuitive approach, etc.) concerning limits have on achievement in calculus '? How does a student's prior conception of the difficulty of calculus affect his achievement in calculus ? Does a unit on limits in Precalculus cause a decrease in enrollment in calculus ? One result of this study was that Treatment group students had an eleven percent lower enrollment rate in Calculus I 89 than did the Control group. This was not statistically significant at the ck = . 05 level, but it was substantial enough to warrant a replication of the study with particular emphasis paid to enrollment. 7. Does a unit on limits in Precalculus result in more; achievement in calculus ? The Treatment group students of this study had an achievement mean 5.9 percent lower than the Control group. This was not statistically significant at the 0k = . 05 level, but it is a justification for replication of the study. The comments of this section suggest a replication of the study. Atten- tion should be directed toward detecing a decrease in enrollment and achieve- ment as a result of Treatment. APPENDICES 90 APPENDIX 1: Instructional Unit LIMITS OF SEQUENCES Examine several sequences and plot them on a number line. Examples: 1, 1/2, 1/3, l/4,... 2, 4, 8,16,... l, - U3, U9, -l/27,... Others Find the 7th, 8th, or 9th terms of each of the above sequences. Find the nth term of each of the above sequences. NOTATION: a,a,a,...,a,... 0r a l 2 3 n n n=1 1 Example: 82:11:] - 1/2, 1/4, 1/6,..., l/2n,... Type of sequences: DEFINITION: An alternating sequence is a sequence whose terms are alter- nately positive and negative. -1 Example: 1, -l/3, 1/9, -1/27,... = '('fi=)r— =1 DEFINITION: A constant sequence is a sequence {an} n=l such that an = K for some constant K. Example: 3, 3, 3.... = (3}nzl 91 Use the above examples to examine "getting close to" (plot on the number line). 1, 1/2, 1/3, 1/4,... —) 0 2, 4, 8,16,... ——-) ? 1, -1/3, 1/9, -l/27,... —-) ? 2, -1, 3/2, -1/2, 4/3, -1/3, 5/4, -l/4,... ——9 ? 3, 3, 3,...—.) ? ASSIGNMENT #1 1. On the number line, plot several terms of the following sequences with given nth terms: -L a) an—2n 2 b) a =1 n+1 n 1'1 C) {('2)}n=1 d) {2“}114 e) {42%) n=1 1 f) {n2+2 n=l g) 1+ (-l) n n=1 2. What number, if any, do the above sequences "get close to"? 92 3. Find sequences (nonconstant) that " get close to" the following: a) l b) -2 c) "a", where a is any number If the terms of a sequence "get close to" some number L, we say that the limit o_f the sequence (an) is L. Since "getting close to" is not precise enough to convey the concept of limit of a sequence, we use the following definition: DEFINITION: A sequence {a\ has limit L if for each C > 0, there is a positive integer N such that if n ) N, then‘a n-Ll ( E. NOTATION: lim a = L my! 11 To illustrate this definition, consider the following examples. Example 1: 1 Let{an}= {F1 andL= o. If G = .01, then an N is 99 (actually, any integer grea er than 99 would also serve as N). Then for n > 99, lEl-T 0./( 01. Ifé = .00001, then N = 99,999. . 1 1 _ Note here that 1f 11 > 99, 999, then n+1) 100, 000 and n+1 100’ 000 - But-“:1- ='—-O), hence‘an-L'(é forn)Nandthe definition is satisfied. Since the choice of N depends on the choice of Q , we usually write NE rather than N as above. 6. 93 Example 2: {a} _ where a = n n-l n For C = .10, find N.10 such that for n) N.10 I an - 0' < E . -1)“ 3n 1 L Try N.10 = 3, then an = 511 and form) 3, 311 < .10. Do the same for 6 = .001. Using the definition of limit of a sequence, it is possible to prove that some sequences have limits. 1 Exam 1e: Prove lim -— = 0- p n4, n+1 Pr00f: Let C ) 0 be given. We then need to find N‘ such that 1 'n+l - 0’ < €whenn)N But 34:1 ((#511—(6931-(m14enr‘l- -1. ' 1 1 Hence for a given 6) 0, let N‘) z- - 1 then for 11) N‘? 2- - 1, l we have n+l)'él-¢P EII/ z Thenn)N‘=}'é‘(n'-'-? ‘nl"<5. ASSIGNMENT #2 l 1. Prove lim -—- = 0 nwmz 2. Explain why the following do not have limits: a) 2, -1, 3/2, -1/2, 4/3, -l/3, 5/4, -l/4,... .2. n+l’ b)a= n n-2 —, neven, n32 11 (Zn)... 3. Let S 1={—} n-1 and G = .001. Find the first (smallest) N 001 such nodd n thatln (..001 l 4. Do the same as in problem number three for {?}n=1 1 What do you conclude about lim ‘2 ? Il-Qod 11 Although the limits of some sequences are attainable by the definition, con- sider a problem such as n2+5n+6 5n+2 xii-’3‘.- (n+2)(n+3)7 °r iii—‘3.- n If we apply the definition here, the work becomes tedious. 95 To facilitate the finding of such limits, we will now prove some basic results which can then be applied to simplify some of the more difficult problems. 1. The limit of a constant sequence is that constant. i.e. 11111 K = K n-hc Proof: Let G > 0 be given and consider the expression Ian - L' < e . lnthiscase,a =KandL=K,hencela -Ll=lK-Kl =0. 11 n We now have the problem of selecting N6 such that for n ) N ‘ , 'an - K’ < e . However, we have already shown that 'an - Kl = 0, hence any N6 we choose will have the desired property, In parti- cular, let N. equal, say, 100. Then for n > 100, Ian - K, ( E and the definition is satisfied. Therefore, lim K = K. n-pv 2. "111.52% = L1 and 33.1%: = L2, then [113.5% + bn ) = Ll + L2. Proof: Let S > 0 be given. Then there exists Nl such that for n ) N1, 6 e _ . an - LII ( 2 . (note that —2- > 0 and III-Ionaan - Ll by hypothes1s). Similarly, there exists N such that lbn - L2|( 5:- for n ) N2. 2 Now consider l(an + bn) - (L1 + L 2)l . By the triangle in equality, (an - Ll)+ (1:)n - L2)|< Ian - Lll + 6 € _ lbn-L2|( —2—+ —2- -€ forn) max {N1’ N2} . (an+bn)-L1+L2l = To illustrate how these theorems can be used, consider the following problems: 5&2 0 511+ 2 a) Evaluate 11111.9” 11 . n—jco n 2 _ . 2: = 111%(5+E)’1113u5+1159a3 5+0 5. 5n 2 _ -r11!21,.$n+n) - 3n +- n 3n n l alua 'm ——2-- = m —-2' + ‘1 = im + "‘ :- b) EV te #11990 n [Iii—ya n n 111_§¢(3 n ) 1 I1131M lim‘fi' = 3+0 = 3. There are several other theorems concerning limits of sequences that will now be stated and illustrated but not proven. 3. If lim a = L , then lim Ka = KL where K is a constant. n—w n l n—)eo n 1 l = 5 . Example: 11.131 0 = 0. 511m oan+l n—pon+l If {1131‘ an = L1 and 11131. bn = L2, then A151. anbn = Lle. (n+2) 1i 1 n+2 = _,,,m+1)(n+2) =n.‘£‘.n+1 n+2 Example: lim 1 1 .1 n+2 0 £~n+l n$n+2 niljnun+l 113'." ' If Almaan = L and bn = an for all n, then [Ill—Tuan = ill—Tubn' At first glance it may appear that this theorem doesn't really say anything. However, it is very important in that it allows us to "reduce" expres- sions. Actually, we have used this theorem intuitively in several of the previous examples . 2n (n + 2) E -————- = lim = , xample: a) 111—?” n (n + 2) n-)ae2 2 2 n +5n+6 1 1 1’) i§¢2(n+2)(n+3) ‘111'13902 '2' an L If $31.08!!le and 111.31.915sz 9‘ 0, then 1113‘?!" = '13:. . n2+n+l . n2+n+l n2 ample. [Ba—T‘sn + 2n - 53.33:; a? - 2 2 n2 + 11 +1 +g+l . 2 lim n = 11m 711 = n-)0‘ n 3n +211 n—M'3n +2n 112 1 + -l- + -1-2 - l 1 lim n n _ 1111-30-0 + n+ n2) _1_ “'7” 3+2 lim (3+ 3) 3 11 mayo. 11 ASSIGNMENT #3 1. step. 6n +13 a) { l3n }n=1 2. Prove theorem three. Evaluate the limits of the following sequences. Give a reason for each n2 + n f) n2 - 2 n=1 2 n 8) n3 + 4 n: 98 a) Let a beasequence such that i a = 0. Prove that n n=l an lim a = 0. [Hm n b) Prove the converse of part (a). (i.e., if 1i ”an = 0, then lim a = 0) n—jv n Prove that if lim a = L, then lim (-a ) = -L. n—non n-)eo 11 Do this both by using the definition of limit of a sequence and by using the results of some of the theorems. LIMITS OF FUNCTIONS We now turn our attention to examining limits of functions. Let us first consider several examples . 1. Let f(x) = x + 2 and suppose x approaches 2 (x—) 2). What is f(x) approaching? (f(x)—9 ?) It is easily seen here that as x "gets close to" two, f(x) "gets close to" four . Let f(x) = x2 and suppose x-—) -1. Then f(x)—? ? 99 3. As a slightly different example, consider _ x+l x50 f(x)-(x+2 x)0 When graphed, this would look like the following: Let us now consider the same questions as on the previous examples. Let x—-) 0. Then f(x)—§ ? After some thought, we realize that there is a need to be more specific about what we mean by x—) 0 and f(x)—9 . It is this need for precision that will eventually lead to the definition for limit of a function. In the meantime, example three illustrates the importance of knowing 1323! x approaches the number we are considering (0 in this case). For example, let x assume the values 1/2, 1/4, 1/6, 1/8, . . . Then the corresponding values of f(x) would be 2 +1/2, 2 +1/4, 2 + 1/6, 2 +1/8, . . . From this it can be seen that f(x)——) 2. On the other hand, let x assume the values -l/2, -1/4, -1/6, -l/8, . . . The corresponding values for f(x) are 1 - 1/2, 1 - 1/4, 1 - 1/6, 1 - 1/8, . .. Accordingly, we would say that f(x)—9 l. 100 This function serves as an example that does not have a limit as x-—) 0. That is because there are two possible values that f(x) is approaching rather than one. We indicate this by saying that as x approaches 0 from the right (x—.) 0+), f(x)—9 2; and as x approaches 0 from the left (x—) 0-), f(x)-—) 1. In examples 1 and 2, it made no difference how x approached the stated num- ber (we usually say "x approached a"). When this is the case, we write 112’ a f(x) = L where L is the number that f(x) is approaching. Hence, in example 1 we would write ’11:? 2 (x + 2) = 4 and in example 2 we would write 113 -l x2 = 1. An adaptation of this notation could also be used for example 3. We would have 11111; 0- f(x) =1 and #3 0+ f(x) = 2. As you might expect, the idea of limit of a function is closely related to the idea of limit of a sequence. The main difference is that in finding the limit of a function it is necessary to know what value the dependent variable is approaching. For example, ’11:; 2 (x + 2) = 4 but 3113} 3 (x + 2) = 5. As before, the idea of "getting close to" is not sufficient for a definition. Therefore, the formal definition for limit of a function as x approaches a is: The function f(x) has limit L as x approaches a if for each 6 ) 0 there isa 5‘) Osuchthatif0( lx-al L 5‘ , then|f(x)-L| ( é . lntuitively, this says that if an interval is placed around L on the f(x) axis, then you can find an interval around "a" on the x axis such that f(x) is in the interval around L for all x 7! a in the interval about a. 101 Example: Let f(x) = 3x - 2 and x—, 2. ThenL = 4. To see how this satisfies the definition, let 6 = 1/2 and con- sider the interval (4 - 1/2, 4 +1/2) about 4 on the y axis. / We now find an interval about 2 on the x axis that satisfies . the definition. VIII: 1‘» for G =1/2, we see that; 1/2 = 1/6 and a su1table mterval would be (2 - 1/6, 2 + 1/6). Foré = 1/10, find a 56 that satisfies the definition of limit of a function. We now show that the interval about "a" depends on the interval about L for thefunctionf(x)=3x- 2witha=2andL=4. 102 (3x-2)-4|<6 é) '3x-6|(£{=§ [3(x-2)|3 Limit Theorems for Functions: As we did with sequences, we now state and prove several theorems that enable us to evaluate the limits of various functions. Theorem 1. Let f(x) = K be a constant function. Then 111.11;. a f(x) = K for any real number a. Proof: Let G- > 0 be given and consider f(x) - K. Since f(x) = K, f(x) - K =0=0, we have that f(x)- L ( E no matter what 106 value of 5 is used. Therefore, 0 ( Ix - a, (5 (say =1) implies [f(x) - LI < E and the theorem is proven. 1 £13 a 30:) = L2. Then £13 a (for) + 800) = £31, a f(X) + 1113 a g(x) Theorem 2. Let f(x) and g(x) be functions such that )liu—n’a f(x) = L and =L1+L2. Proof: Let G, ) 0 be given and considerl (f(x) + g(x)) - (Ll + L2)|. As before, we have by the triangle inequality |(f(x) + g(x)) - (Ll + L 2)l =|(f(x) - Ll) + (g(x) - 1.2)]; [f(x) - LII + [g(x) - LZI‘ But since 1’ there is a S I such that 04—.lx - al ( ‘1 implies |f(x) - Lll ( 6/2 and since 41.3.13“): L2, there is a ,5 2 lim f(x) = L x-)a such that 04 [x - al 4 52 implies' g(x) - Lzl ( ‘/2. Hence rot-J = min {5"} 11,0 ( Ix - al ( J implies both |f(x) - Lll L 5/2 and |g(x) - Lzl L 5/2. Therefore '60:) + 200) - (Ll + 1.2)] 6 lfix) - LII + |g(x) - LZI 4 ‘/2 + €/2 = 6 . This then satisfies the definition and we have x113 a (f(x) + g(x)) = L+L. 1 2 Example: Let f(x) = 3x2 and g(x) = 5. Then £3; 2f(x) =12 and 2 2 li =5 dli 3x+5=lim3x+ 5= x323“) an x32< ) x—n :52 12+5=l7. Theorem 3. Let f(x)beafunction such that 1121, af(x)=Landletheanon- zero constant. Then lim Kf(x) = K ° L. x—aa 107 Proof: Let G ) 0 be given and consider Kf(x) - KLl . By properties of absolute value, we have |Kf(x) - KLl = IK” f(x) - Ll . Then le(x)- KL|( £9 “(Him-1.1459 [f(x)-q ( 5m . But since lim f(x) = L, we know there is a S ) 0 such that x—-)a 0 (Ix - a| (S =} |f(x) - Ll ( G/|l(| . Therefore for é) 0, thereisa S > Osuchthat0( Ix-al 45:} lf(x)-L| < 6/|1<|=.9 |1<| |f(x)- L] (6 =) le(x)- KLI (e . This then satisfies the definition and we have lim Kf(x) = K ' L. x—)a Example: Let f(x) = 3x2 + 5 and suppose lim x_’2 2 2 = ' + ' = ' = ° :7. J11m23x £325 3,1132x +£1m25 3 4+5 1 2 2 = . + x 4 Then x113 2 (3x 5) There are several other theorems involving limits of functions that will now be stated but not proven. Theorem 4. Let f(x) and g(x) be functions such that )liin’ a f(x) = L1 and Jlei-n; a g(x) = L Then 123 a f(x) g(x) = 2. Lle. Theorem 5. Let f(x) and g(x) he functions such that 1113 a f(x) = L and 1 f(x) __ L] lim ag=(x) L2 #0. Then 13a“? L2. Theorem 6. Let f(x) be a function such that lim af(x)= L 0. Then lim a\n/ f(x) =\n /lima f(x) =VL—. 108 Theorem 7. Let f(x) and g(x) be functions such that f(x) = g(x) for all x except = . Th 1' = 11 'd . x a en x12) a f(x) x 23a g(x) prov1 ed these limits exist . x - 9 . z = = . Example (Theorem 7) J11m 3 x _ 3 1115 3 (x + 3) 6 The following examples illustrate how the previous theorems can be used to simplify and evaluate the limits of several functions. 2 . 2 x 123 x I . = x 3 Example. ’12 3 _ 2 (limit of quotient) 11133 (3x - 2) 9‘13 3 x) (Ly-n“ x) (limit of product) lim (3x - 2) x—) 3 = _____5 (previous problems) I \llxo Example: (Indicate the reason(s) for each step) + - 11m Lil : lim (x+3) (1;+2) x—,+2V “‘2 x—)+2 x' (x+3)(x- 2) VEBH x- 2 V 11m (x + 3) x—-)+2 V 5 109 ASSIGNMENT #6 Find the limits of the following functions. Give reason(s) for each of your steps. a) lim (x2-3x+5) x—-)3 b) lim ‘3'“; c) lim d) lim e) lim £2“.-é x—,2 x -4 V3+x -y3 0 x f) lim x-’ Letf(x)=l. Provethat l' -l- =-1 by x x3 2 x 2 a) theorems from this section. b) using the definition of limit of a functiOn. Let f(x) be a function. Prove that £13 a f(x) = 0 iff £13; a f(x)| = 0. Let f(x) be a function such that lim f(x) = L. x—)2 Prove that 12.32 |f(x)| =l 14 . 110 5. Give an example of a function f(x) that does fl have a limit as x—-) 3. 6. Give an example of a function f(x) that does 93$ have a limit as x——) 3 but is such that lim f(x) = l. x—)3 111 APPENDIX 11: Daily Classroom Record for Treatment A Wednesday, October 17 About thirty minutes of the fifty minute period was spent on the new unit. Students were made aware of the following groups involved in the study: (a) mastery treatment, (b) regular treatment, and (c) control. The stu- dents were also informed of impending interviews at the end of the semes- ter. During the general discussion, students were informed that they would still cover the core of material in the regular Precalculus course. The remaining instructional time permitted a discussion of notation, definitions, and examples preceding Assignment One. Assignment One was then given for Thursday. Thursday, October 18 Problems associated with the assignment were discussed. Quiz number one was given. The definition of page three is difficult to comprehend. lntuitively, the students seem to have no difficulty with the concept of limit of a sequence. There is some confusion between "n" and "N". To alleviate this, a proof should be carefully checked tomorrow. Friday, October 19 Assignment T\vo was reviewed. Quiz 2a was given and 2b was assigned to be turned in on the following Tuesday. Two theorems were proven. They were: (1) lim K = K, where K is a constant n on (2) If {83114 and {bnknfl are sequences such that m’an = L1 = + = + and I1113mm! L 2, then r111$".(an bn) Ll L 2 There really was not enough time today. The second theorem was finished right at the end of the period. Consequently, there was no time for illustration and application of the results. Absence was a real problem today. Sixteen of the total of sixty were not in class. This will make working with the definition diffith for those not in attendance since this was our first good look at the proof of a theorem using the definition. 112 Tuesday, October 23 A brief review of previously presented limit material was given. Limit theorems three through six on page six were presented and illustrated. Proofs of these were omitted. Several examples illustrating the appro- priate use of these theorems were given. Assignment Three was made for Wednesday. Wednesday, October 24 Questions concerning Assignment Three were answered. Because of the difficulty encountered with problems three and four of this assignment, problem 3a was worked in class and then students were asked to turn in either 3b or 4 on Thursday. Quiz number three was given in class. The last fifteen to twenty minutes of class time was spent discussing the intuitive concept of limit of a function. Thursday, October 25 The first section on limits of flmctions was finished. The definition and appropriate notation were covered in this section. Assignment Four was given for Friday. Friday, October 26 Questions from Assignment Four were answered. Students have less trouble working with the definition this time than they did before. Quiz number four was given. Absence is still a problem; eighteen students were missing today. Section number two on limits of functions was finished and Assignment Five was given for Thesday. Thesday, October 30 Questions were answered about the assignment. The last section was completed today. As before, only two theorems were proven in class. They were: (1) Let f(x) = K be a constant function. Then ‘11:; a f(x) = K for any real number a. (2) Let f(x) and g(x) be real-valued functions such thatILin; a f(x) = L1 and Jar-n, a g(x) = L2. Then #2; a(f(x) + g(x)) = Ba f(x) + l . = x.135 a g(x) Ll + L2. 113 The rest were stated and illustrated. Assignment Six was given for Wednesday and quiz number five was assigned to be turned in Wednesday. Wednesday, October 31 Questions about the assignment were answered. Quiz number six was given. The rest of the period was used as a general review for Thursday's test. The students are aware that this test is a formative evaluation. Instructions to the class about testing were reviewed as follows: (1) You may take the retest regardless of your score. (2) The tests will be returned with diagnostic sheets on Friday, the first alternative instruction session. (3) Other alternative instruction sessions will be held on Monday at 8:00 a.m. , 9:00 a.m. , and 7:00 p.m. to 9:00 p.m. Tuesday's regular class period will also be used for alternative instruction. (4) The summative evaluation will be given on Wednesday, Nov. 7. Frustration seemed to be a big factor today. Thursday, Novemberl A formative evaluation was administered to both sections. 114 APPENDIX III: Quizzes Write the fifth term of the sequence { -l)n + n 1 n=1 1 1 (a) For the sequence {72;} and G = 36 , find N such that n=1 1 l I-Z‘EI < '56 for n > N. l (b) Prove xii-$.53 = 0 using the definition for limit of a flmction. Evaluate the limit of the following sequence. State a reason for each step. 2n2+3n- 5 3n2-n+4 n=1 1 1 Letflx)=2x+landlet(7- 15. 7+ 1‘6)beanintervalabout7onthe f(x) axis. Find the associated interval (3 - 5 , 3 + S ) about 3 on the 1 l xaxis suchthatifxisin(3- 5, 3+ 5), thenf(x)isin(7- IT)” 7+ i6). Prove gilt-1’3 (2x + l) = 7 using the definition of limit of a function. , x Find ’11:; 2 x __ 2 . State a reason for each step. 115 APPENDIX IV: Summative Evaluations - Treatment B MATH 120 Name LIMITS - A (11 pts.) Explain why the following sequence does not have a limit. (Hint: Plot the terms on the number line). 1 {(4)n + ‘11-} n= (12 pts.) Give an example of a nonconstant sequence whose limit is -2. Include reasoning. (12 pts.) Give an example of a function that does not have a limit as x-—)1. Include reasoning. (15 pts.) For the following sequence, find the smallest N 1 such that 1 Io_o [an - 3' < I‘D-6 forn) NJ...’ Show your work. 100 3n + 2 :1 n=1 2 (15 pts.) Evaluate lim 2 - ' . Give the reasons for each step. nfi~3n + 5n + l 2 x + 5x (15 pts.) Evaluate £3 0 ‘7_x _ 2x . Give the reasons for each step. (20 pts.) Prove, using the definition of limit of a function, that f34(3x-2) =10. 116 MATH 120 Name LIMITS-B l. (11 pts.) Explain why the following sequence does not have a limit. (Hint: Plot the terms on the number line.) H)“ - é n=1 2. (12 pts.) Give an example of a nonconstant sequence whose limit is -1. Include reasoning. 3. (12 pts.) Give an example of a function that does not have a limit as x—) 2. Include reasoning. 4. (15 pts.) For the following sequence, find the smallest N 1 such that 1 '1'0-0 I; -3l(i-0-5forn> N1 . Showyourwork. n — 100 6n+1 2n - n.— 5 Eal li 38-23” Gi th to h . (lSpts.) v uaten'_11r_1”.‘m:5:n_5 . ve ereasons reac step. 2 -x + 6x 6. (15 pts.) Evaluate )l‘im O T + x . Give the reasons for each step. 7. (20 pts.) Prove, using the definition of limit of a function, that iii-133(k-l)=ll. 117 APPENDIX V: Formative Evaluation - Treatment A MATH 120 Name LIMITS-C 1. (11 pts.) Explain why the following sequence does not have a limit. (Hint: Plot the terms on the number line.) 1 {9 2)n + 1:} n=1 2. (12 pts.) Give an example of a nonconstant sequence whose limit is -3. Include reasoning. 3. (12 pts.) Give an example of a function that does not have a limit as x—9 3. Include reasoning. 4. (15 pts.) For the following sequence, find the smallest Nl such that 1 1‘66 an- 3| (I55 forn) NJ...’ Showyourwork. 1 {3n - 3 n n: 2 5 s Eal 11 "in ”+16 Gi th f h . (1 pts.) v uate 113092112 - 5 . ve ereasons or eac step. 3+ 3::2 - 2x 6. (15 pts.) Evaluate Jlim . Give the reasons for each step. —)0 2x3-5x 7. (20 pts.) Prove, using the definition of limit of a function, that 121—“)1 (7x- 5)=2. 118 MATH 120 Name LIMITS - D (11 pts.) Explain why the following sequence does not have a limit. (Hint: Plot the terms on the number line.) .1 n n=1 (-2)“ - (12 pts.) Give an example of a nonconstant sequence whose limit is -5. Include reasoning. (12 pts.) Give an example of a function that does not have a limit as x—) 4. Include reasoning. (15 pts.) For the following sequence, find the smallest N I such that l 100 Ian - 3| (IO-0’ forn) N_l_. Showyour work. 100 {gm 3n n=l 6n3 +1011; 1 (15 pts.) Evaluate I1111‘. A; .7113 + 4nl _ 2n° Give the reasons for each step. 3x2+2x (15 pts.) Evaluate 111m 2 + 5x -) 0 -2n . Give the reasons for each step. (20 pts.) Prove, using the definition of limit of a function, that Jl‘i‘_r_x;6(4x+5) = 29. 119 APPENDIX VI: Summative Evaluation - Treatment A MATH 120 -- Limits Name (a) (12 pts.) Give an example of a nonconstant function f(x) such that lim f(x) = 5. Include explanation. x—’ 2 (b) (12 pts.) Give an example of a sequence of positive terms that does n_o_t_ have a limit. Include explanation. (c) (11 pts.) Explain why the following function does not have a limit asx—)-1. f - x+l,x£-l 0‘)— 3,x)-l (15 pts.) For the following function, find 5 1 such that 1000 l |f(x)-l3l (165.5 when0( lx-6l ( 51 . 1000 f(x)=2x+l, a=6, L =13. 2 -2 + - 3 (15 pts.) Evaluate lim n T n . Indicate reasons for each step. n—no 4n - 5 3 x - 4x T (15 pts.) Evaluate £13 2 x3 + x _ 6x . Indicate reasons for each step. (20 pts.) Prove, using the definition of limit of a sequence, that 11 n-3n2 _ 3 1133ng " ° 120 APPENDIX VII: Instructional Alternative Worksheets WORKSHEET l Explain why the following do not have limits: [I n 2. {(-2 )} n=l 11 3° {3 } n=1 1 4. {411+ 3} n=1 4 5. f(x)= {ght-S: a=5 x+l,x£--3. _ 2x,x)-3' “"3 0‘ C :2 X V II I x 1 ”N >1 ‘0. N 9) II N 7. f(x) - 121 WORKSHEET 2 In the following problems, for the given 6 , find the corresponding N g or J‘ . l 2n+l lo 6 i6! { n }n= L=2 l -3n+4 2- €= 17.66{T} L“ n=1 1 3. e = 1'55. f(x) = 3x+1,a=2,L=7 NIOD 1 4. e: 35, f(x) = -2x,a=0,L=O 1 5. 6: 555,:(x)=-3x+1,a=2,L=-5 122 WORKSHEET 3 Evaluate the limits of the following: l 3n3-2n2 ' -2nr+n-l =1 x2-9 2. f(x) = x-3’ a=3 3 f 4x4+3x3-x2 -0 e (x) _ 2114-3x2 a a" 21124-1 4. 3 -4n +2n-S n=l + 5. {11111} n=1 6 f x2+6x+9 _ 3 ° (x) - x7+5x+6 ’ a— x2+6x+9 7. f(x) = , a=0 x2+5x+6 123 WORKSHEET 4 Using the definition of limit, prove the following. + 6.11m2nl=2 n-pon 7.li=0 124 APPENDIX VIII: Attendance Summary for Alternative Instruction Sessions Session Date Time Number Attending Friday 8:00 a.m. 22 Group Lecture Friday 9:00 a.m. 31 Monday 8:00 a.m. 10 Monday 9:00 a.m. 23 Small group Monday 7:00 p.m. 29 sessions Tuesday 8:00 a.m. 24 Tuesday 9:00 a.m. 27 TABLE A.1 Attendance Summary for Alternative Instruction Sessions 125 APPENDIX IX: Calculus Tests MATH 202: Test 1A 1. Prove: lim (ax+b) = ac+b He x2 - 5 + 6 2. Find lim x . Use only one step each time a limit concept is x-) 3 x2 -4x + 3 used and give the reason for that step. For problems 3, 4, and 5, give an example of a function f such that: 3. fhasarighthandlimatz, fhasalefthandlimatZ, but hm; does not exist. 4. £111, 1; exists and is positive for all real numbers, a. 5. J1131,31“ exists and = f' (a). (Give both f and a) 6. (a) Give the definition of : "f is continuous at a if. . (b) Tell where f is continuous and where not continuous if 2- x 3x+2 ifx 7, 2 f(X) =.- x-2 3 ifx = 2 2 7. (a) (3x3-2x2+x-4- i)‘ = (1» «x2_ 3x) - (x3+s»' = x3+4x (C) 2x+7 = (d) ((x2 - 3x + 010), = 126 MATH 202: Test 1B 1. Prove: lim (ax+b) = ac+b x_.) c 2. Give one reason for each step using a limit concept and evaluate xg- 5x+6 m3xz-4x-i'3 For problems 3, 4, and 5, give an example of a function f such that: 3. lim f exists and is positive for all real numbers, a. Ha 4. lim+f exists, lim -f exists, but lim f does not exist x-—-)2 x—)2 x--)2 5. lim f exists and = f'(a). (Give both f and a) x-—)a 6. (a) Define: "f is continuous at a if. . (b) Tell where f is continuous and where not continuous and give reasons for your conclusions if. . . 2 x --3it+2 ifx #1 f(x) = x 2 ifx =1 3 7. (a) (4x3-x2-21t+5- E" = 2 (b) «x +2x> - (x3-7»' = . x3-3x , (C) 4x+2 (d) «x2 - 5x +1>‘2)' = 127 MTH 202: Test 1C 1. Prove: lim (ax+b) = ac+b x—) c 2. Give one reason for each step using the limit concept and evaluate: 1. x2 - 5x + 6 1m 2 x—’3 x - 4x + 3 For problems 3, 4, and 5, give an example of a function f such that: 3. lim + fexists, lim - fexists, but lim a does not exist x...’ 3 x.) 3 x—’ 4. 11m" f exists and is positive for all real numbers, a x a 5. lim f exists and = f' (a) (Give both f and a) x—9 a 6.. (a) Define: "f is continuous at a if. . (b) Tell where f is and is not continuous and give reasons for your conclusions if 2 xx-3lx+2 ifxifl f(x) = 5 ifx =1 7. (a) (5X3-3x2+x-1+-:-)’ = (b) <- (3x +5”! z 2 x +2 (C) (ans), "' (d) ((4x2-3x+7)10)’ = 129 MTH 202'. Test IE 1. Prove: If n is a negative integer, then (inn), = nx 2. Evaluate using one step each time a limit concept is used. Give the reason to find 11m x3-7xth H5 xZ-6x+5 For problems 3, 4, and 5, give an example of a function f such that: 3. lim f+ exists, lim f_ exists, lim f does not exist, and f(x) is not x-’ 4 x—-) 4 x—) 4 the GI function 4. lim f exists and is negative for all real a x-ga 5. limf exists and = f'(a) (Give bothfand a) a 6. (a) Define the derivative of a function, f, at x (b) Use this definition to find i ' (x) if f(x) = lb— 3 (c) Evaluate lim x w 35. w—}O w x1... 2 l 7. (a) (4x -3x+4+;)l = (b) ((x2+5x) . (2x3+7))' = 2 x -7 (c) (9x+4 I: (d) ((7x2-8x+5)12)’ = 130 APPENDIX X: Description of Random Selection Procedure for Interviewees After deciding upon the number of students to be interviewed in each group, the following procedure was utilized: (1) (2) (3) (4) the students in each group were numbered according to their alphabetical listing. a page and a column in the random number tables was selected by a random number. from the randomly selected starting place, the column was read down until the desired number of digits were located (for example, if twenty-one students were in the list and five were needed for interviews , one would continue down the column until locating five digits (numbers) less than or equal to twenty one). using these numbers, the corresponding names in the list were selected for interviews. 131 APPENDIX X1: Interview Questions NAME DATE GROUP 1. Status at C.M.U. 2. High School attended Size A B C D Other 3. Class rank 4. Mathematics courses taken prior to Precalculus 5. Why did you take Precalculus ? 6. How are you doing in Precalculus ? 7. How do you like Precalculus ? 8. Is Precalculus harder or easier than you expected? In what ways ? 9. (Where applicable) What is your reaction to the section on limits ? 10. Do you presently plan on taking Calculus 1? Why or why not? 11. Did you previously plan on taking Calculus I? 12. If not included in number 10 above, indicate reasons for differences if they exist in number 10 and number ll. 13. How difficult do you think Calculus I will (would) be compared to other mathematics courses you have taken? 14. How do you think you will do in Calculus I? (Where applicable) Interviewers Reaction Briefly discuss your conception of student anxieties or lack of anxieties regarding Calculus I. What is your opinion of the student's attitude toward Calculus I? 132 APPENDIX XII: Questionnaire Given to Calculus Students Name Name of Precalculus instructor (if any) Semester Precalculus was taken (if any) In the following, please check the appropriate response: 1. Compared to what I expected, Precalculus was: a. much harder b. harder c. about the same (1. easier e. much easier 2. So far, compared to what I expected, Calculus I is: a. much harder b. harder c. about the same d. easier e. much easier 3. Compared to other material you have studied, limits are: a. most difficult b. somewhat hard c. about average d. easy e. very easy 4. I have spent the following number of hours per week (outside of class) studying limits so far this semester: a. 0-5 h. 6-10 c. ll-lS (1. 16-20 e. Other (please specify) In some instances, one can distinguish between degree of difficulty of a subject and the level of frustration encountered when studying the subject. With regard to this, the following question is an attempt to discover how frustrating the study of limits is rather than how hard it is. S. I find the study of limits this semester: a. very frustrating b. more frustrating than average c. average d. less frustrating than average e. no frustration 133 Noncommom 32:35 I N .4 was. N N N N N N N N manages Noe N N N N N N N N N N Neheou N N N N N N N N N N N N N N N N N N N N N 333582 N N N N N N N N N N N N N N N N N N N N N teens 350 N N N N N N N N N N N N N N N N N N N N N .558 N338 N N N N N N N N 333% N8 N N N N N N N N N N Nohdoo N N N N N N N N N N N N N N N N N N N N N €335.32 N N N N N N N N N N N N N N N N N N N N N been: N N N N N N N N undies Noe N N N N N N N N N N Nobeoo N N NN N N N N N N N 2 N N N N N N N N N 2 5583 N N N N N N N N «Benzene Noe N N N N N N N N N N Nohdoo N N N N N N N N N N N N N N N N N N N N N N 338$ N N N N N N N N N N N N N N N N N N N N N 4 3.53:. N N N N N N N N cascades Noe N N N N N N N N N N Nassau N N N N N N N N N N N N N N N N N N N N N szN N N N N N N N N N N N N N N N N N N N N N 2N N N N N N N N N N N N N N N N N N N N N N 222 N N N N N N N N N N N N N N N N N N N N N 292 N N N N N N N N N N N N N N N N N N N N N :82