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dissertation entitled

THE IMPACT OF THE MICROCOMPUTER-BASED LABORATORY

IN LEARNING PHYSICS CONCEPTS
--A CASE STUDY OF THE PSL

presented by

Shezhang Wu

has been accepted towards fulfillment
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Was-9.1

THE IMPACT OF THE MICROCOMPUTER-BASED LABORATORY IN
LEARNING PHYSICS CONCEPTS
--A CASE STUDY OF THE PSL .

By

Shezhang Wu

A DISSERTATION

Submitted to ‘
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Educational System Development

1995

THE IMP

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ABSTRACT

THE IMPACT OF THE MICROCOMPUTER-BASED LABORATORY IN
LEARNING PHYSICS CONCEPTS
--A CASE STUDY OF THE PSL

5V

Shezhang Wu

This research used the method of qualitative/ethnographic research to investigate
the impact of microcomputer-based laboratory (MBM) activities in learning physics
concepts. The MBL tool was the IBM Personal Science Laboratory (PSL) package,
consisting of hardware and software used together to provide science learning
experiences. The research sites were located in a school district in Michigan and at
Michigan State University. A total of 23 subjects participated in this research, 4 high
school students, 16 middle school students, 2 graduate students, and 1 elementary school
teacher.

in this study, the subjects' activities were observed at three levels. At the first
level, subjects performed step-by-step procedures to complete three specific
temperature experiments. At the second level, subjects designed experiments in
different ways to collect and analyze data. At the third level, subjects combined parts of
capabilities within the PSL program to solve some general problems.

The research results indicated that:

The PSL program enhanced subjects' abilities to discover some
challenging concepts with the use of computer graphs which were not readily

available in the traditional classroom lecture or experimental labs.

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The PSL‘s capability of integrating science, mathematics and computer
technology allowed subjects to repeat experiments as needed several times during
a lab hour--thus contributing to better understanding.

Subjects who had strong subject-matter background in physics and/or
mathematics, and with strong computer knowledge could explore some complex
approximations using the PSL that they would not have been able to explore in a
traditional physics class.

The availability of immediate feedback, and the ability to reverse
operations and present data in both graphical and tabular form provided a means
for some subjects to better understand the calculation process is for data
analysis.

The graphs provided by the PSL generally enhanced the subjects‘ abilities
to view the experimental results from various perspectives.

The PSL was a user friendly program. Subjects from middle to graduate
levels were able to use it easily and proticiently to learn physics concepts. The
PSL provided motivation for subjects at different levels of educational
competency.

The PSL provided an arena for students who had advanced computer
experience and subject-matter background to explore experiments in greater
depth.

The PSL supported and encouraged collaborative learning for some
subjects.

in general, the PSL software and hardware provide an excellent

experience for learning physics concepts.

To my parents, Yin Fen Lin and Guan Wo Wu,
who introduced me to the wonder of learning.

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ACKNOWLEDGMENTS

Many friends and my family have supported me. I would like to thank those who have
made significant contributions to my learning environment:

To Dr. Richard McLeod, my committee Chairperson, for his professional support and
inspiration throughout my years in graduate school.

To Dr. Lawrence Redd, my committee member, who has supported my academic
efforts with patience and kindness.

To Dr. Glenn Berkheimer, my committee member, for his enthusiastic support in
helping me achieve my goal.

To Dr. Leighton Price, my committee member, who shared his expertise in my
dissertation writing.

To Dr. Marie Emery, my former supervisor in the Media Lab and Computer Access
Center of College of Education for six years and committee member, for her
support of both my academic and financial situations.

And especially do I acknowledge Zhongyi Huang, Yanwen Wu and Chaowen Wu-my
wife and two children for the hardships they undertook to do tasks at home that l
was not able to accomplish because of the time needed for research and writing.

LISTl

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TABLE OF CONTENTS

LIST OF TABLES .............................................................................................................. viii
LIST OF FIGURES ............................................................................................................ ix
CHAPTER I. INTRODUCTION TO THE STUDY ................................................................. 1
Statement of the problem ................................................................................ 1
Rational of the multiple perspectives for this study ................................. 5
Summary of the Research Foci ...................................................................... 17
Significance of This Study .............................................................................. 18
Overview of All Chapters ................................................................................. 19
CHAPTER 11. REVIEW OFTHELITERATURE ................................................................ 20
How people interact with the computers differently ................................ 21
The role of computer simulation and approximation in learning
physics concepts ............................................................................................... 26
The Real-World Computer-Oriented experiments and its
computation ....................................................................................................... 34
The role of MBL in learning physics concepts ........................................... 35
The roll of collaborative learning ................................................................ 44
Summary of the Literature Review ............................................................... 48
CHAPTER III. DESCRIPTION OF RESEARCH METHODOLOGY ....................................... 5 0
Method chosen for this study ......................................................................... 50
Qualitative Method vs. Quantitative Method ................................................. 51
The validity of the Qualitative Method .......................................................... 52
Subjects ............................................................................................................... 53
Sites ..................................................................................................................... 56
Subjects' Activities ........................................................................................... 56
Data collection ................................................................................................... 58
Methods of data analysis .................................................................................. 64
Summary of this Chapter ................................................................................ 66

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CHAPTER IV. DATA PRESENTATION, DISCUSSION AND FINDINGS ........................... 67

Overview of the data presentation ................................................................ 67
Research Foci One

To what extent subjects learn physics from the .PSL

program? ................................................................................................ 70
Research Foci Two

What computer skills do subjects gain for future research

from the PSL? ........................................................................................ 88
Research Foci Three
What approximation skills do subjects gain from the PSL? ......... 101

Research Foci Four

Do subjects understand the calculation process when the

PSL does all the calculation? .............................................................. 118
Research Foci Five

To what extent do computer graphs help subjects

understand the subject-matter knowledge of physics and

mathematics? ......................................................................................... l 29
Research Foci Six

Do subjects‘ attitudes towards the use of a computer change

as they get computer experience while using the PSL? ............... 139
Research Foci Seven

Do subjects who have both computer skills and subject-

matter knowledge interact with the PSL differently from

those who do not have?............... ........................................................ 146
Research Foci Eight

Does the PSL support and / or encourage collaborative

learning? ............................................................................................... 164

Research Foci Nine
Does PSL improve the computer readiness of a teacher? ............. 175
Chapter Summary ............................................................................................. 179
CHAPTER V. SUMMARY, FINDINGS AND RECOMMENDATIONS ................................ 180
Summary of the results of the three level procedures ............................. 180
Findings from the research questions ......................................................... 182
Discussion ........................................................................................................... 1 8 5
Recommendations for further research ...................................................... 190
Suggestions for improving physics education with the PSL ................... 203
Concluding thoughts ........................................................................................ 204
APPENDICES .................................................................................................................... 205
LIST OF REFERENCES ...................................................................................................... 23 5

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Table 3-1 Subjects' general information ................................................................. 54
Table 4-1 Purpose, activities and how many subjects at each level ................... 69
Table 4-2 Experiments, grade level and participation ......................................... 69
Table 4-3 Responses from subjects who had not taken physics ......................... 70
Table 44 Responses from subjects who had taken physics ................................ 72
Table 4-5 Answers from subjects who had not taken physics ............................ 77
Table 4-6 Answers from subjects who had taken physics ................................... 77
Table 4-7 Summary of the experiments of the Simple Harmonic Motion ........ 95
Table 4-8 Summary of responses to ADD 8: SUBTRACT ................................... 119
Table 4-9 Summary of responses to MULTIPLY 8: DIVIDE ............................... 122
Table 4-10 Summary of the subjects' attitude toward the use of PSL .................. 139
Table 4-11 Subjects' computer background ............................................................. 146
Table 4-12 Subjects' subject-matter background ..................................................... 147
Table 4-13 Summary of subjects' interaction in group 1 ........................................ 148
Table 4-14 Summary of subjects' interaction in group 2 ........................................ 148
Table 4-15 Generalization of Table 4-13 and Table 4-14 by comparing

Group 1 and Group 2 ............................................................................... 164
Table 4-16 Subjects' work style and levels of completion ..................................... 164
Table 4-17 Collaboration vs. grade levels ................................................................ 175
Table 5-1 Summary of the Results of the Three Level Procedures .................... 181

viii

 

 

 

 

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LIST OF FIGURES

Figure 2-1 A model of motivation, performance, and instructional

influence .................................................................................................. 25
Figure 2-2 Carol described how she understood the resultant velocity

by using a metaphor of pulling ........................................................... 29
Figure 2-3 From the simulation graphs, the velocity arrows seen

pivoting about its base, Carol used a metaphor of hinging to

comprehend how the direction of trajectory changes ...................... 30
Figure 2-4 Displacement vs. time on a symmetric double ramp for four

different cylinders noodle soup, soda pop, solid aluminum,

tomato soup ............................................................................................ 40
Figure 2-5 The experiment arrangement—Symmetrical double ramp .............. 41
Figure 2-6 Displacement and velocity vs. time for an aluminum cylinder

on the double ramp. Letter A through H identify points for

students to describe ............................................................................... 42
Figure 2-7 Teacher-student's communication ...................................................... 46
Figure 2-8 Student-student collaborative learning .............................................. 47
Figure 4-1 Question about the pendulum clock ................................................... 76
Figure 4-2 Simple pendulum experiment set-up ................................................. 78
Figure 4-3 Incorrect pendulum wave .................................................................... 79
Figure 4-4 Correct pendulum wave ....................................................................... 79
Figure 4-5 Subject 4's idea in measuring the pendulum period ........................ 82
Figure 4-6 Subject 19 8: Subject 20's Whole length simple pendulum

data ........................................................................................................... 92
Figure 4—7 Subject 19 8: Subject 20's whole length simple pendulum

calculation ............................................................................................... 93
Figure 4-8 Subject 13 8: Subject 14's Long String simple pendulum data ....... 94
Figure 4-9 Subject 13 8: Subject 14's Long String simple pendulum

calculation ............................................................................................... 94
Figure 4-10 Subject 11's Fit-line Equation-1 ............................................................ 96
Figure 4-11 Subject 11's Fit-line Equation-2 ............................................................ 97
Figure 4-12 Subject 11's Fit-line Equation-3 ............................................................ 97
Figure 4-13 Subject 11's Mass 8: Spring Oscillation data ...................................... 99
Figure 4-14 Subject 11's errors .................................................................................. 100
Figure 4-15 Subject 21's Body Temperature ............................................................ 102
Figure 4-16 A column with a formula =LOG(A4) ................................................. 103
Figure 4-17 Graph of LOG(A4) vs. experimental graph ....................................... 104

 

 

 

 

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After adding 33.44 ................................................................................. 105
A column with a formula =LOG(A4)/LOG(9) .................................. 106
Graph of LOG(A4)/LOG(9) vs. experimental graph ....................... 107
Cooling ........................................................................ ' ............................ 1 08
After applying LOG(base 10) ............................................................... 109
A column with a formula
=0.01802*COS(Z*PI()*1/2*A3)+0.01802 .............................. 111
Pendulum Approximation ................................................................... 112
Determining K (constant) ..................................................................... 113
Finding the spring constant K by using the Fit-line equation ......... 114
Before adding 2 to a graph ................................................................... 120
After adding 2 to the graph .................................................................. 121
Two columns with formulas =360‘1/2‘A4 and

=SIN(2*PI()*1/2*(A4) ............................................................................. 125
Graphs of =360‘1 /2*A4 and =SIN(2*PI()*1 / 2*(A4) .......................... 126
The pH value was increasing ............................................................... 131
The pH value was still increasing ....................................................... 132
The pH value increased and then became stable at 7.5 .................... 132
There was a little pot ............................................................................. 133
A set-up of Temperature vs. Time ...................................................... 156
A set-up of Temperature vs. pH .......................................................... 156
Subject 4's idea in finding the pendulum period .............................. 157
A set-up of PH vs. Time ........................................................................ 159
Creating a set-up to collect two kinds of data ................................... 159
Subject 2's set-up of pH vs. Temperature ........................................... 160
A comparison of Subject 1 and Subject 2's set-ups ........................... 161
Subject 23's temperature graph ............................................................ 176
Subject 23's pendulum wave was flat ................................................. 177
Simple Pendulum's wave (after scale) ................................................ 178
Subject A-subject B collaborative learning ......................................... 188
Exploring Newton's Second Law by using the PSL ......................... 195

 

 

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CHAPTER I
INTRODUCTION TO THE STUDY

Since the development of the motion detector in the 19805 (Taylor, 1990), more
and more versions of the Microcomputer-Based Laboratory (MBL) hardware and
software have become available. However, an exhaustive search of the literature has
revealed only three studies on the impact of MBL's on student learning.

The problem that led to this study is identified below.

Wm

The research problem of this study is to determine whether using a MBL shifts
students' focus to new Ieaming strategies, and if it does, to what extent does it effect
Ieaming physics concepts. I

This study investigates the PSL (IBM's version of a MBL) program's capabilities
in order to answer questions concerning the impact of the MBL environment on students'
Ieaming of the physics concepts.

The IBM Personal Science Laboratory (PSL) is one version of a MBL. It provides
an opportunity for students to gather data more quickly and more easily than they could
without this kind of device. For example, the motion sensor can take distance
measurements 40 times per second-"far more frequently then one could ever
accomplish manually. Furthermore, the software has the capability to calculate velocity
and acceleration based on the changes of distance overtime and displays these data on a

graph. The axes of a graph can be determined by a student. In addition, the software

 

 

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permits manipulation of the data in a variety of ways including adding constants, taking
logarithms, integrating, etc. Thus the MBL has the potential of shifting the emphasis in
Ieaming physics concepts from laboriously gathering and plotting data to analyzing data
in various ways and making it easier to understand the implications of the data.

The rationale for this problem was drawn from the dire need to improve learning
of the physics concepts.

Dissatisfaction with student desire to learn physics concepts both in high schools

and in colleges has been voiced by Bork (1990) and others. Bork states:

At the beginning of this century most graduates of secondary school in the
United States had physics as one of their courses. Currently only a small
fraction of secondary school students take physics. The number of
students taking physics in secondary school has declined all through this
century. There was some slight changes in this pattern during the
development of the new curriculum, about 1960, but this was temporary.
Many now think that physics should be taken in secondary school only by
the few students who absolutely need it for the future. Counselors
actively urge students not to take physics unless these students are
exceptional or are pursuing careers for which physics would be
essential."...(p32) “The situation has deteriorated to the point that a
recent survey done by the National Science Teacher's Association shows
that only about half the high schools in the United States currently offer a
physics course. Far fewer high schools offer advanced-placement
physics courses, and these high schools usually cater to the children of
the wealthy. The data also show that about half of the teachers currently
teaching physics are not certified to teach physics. As with physics
enrollment, these figures have been moving in the same monotonic
direction for long periods of time. The situation is a disaster. (p. 33)

This dissatisfaction with high school students' desire to Ieam physics concepts
could be addressed by making teaching and Ieaming physics easier and more attractive so
that more students would be encouraged to take physics and succeed in Ieaming it. Also,
making physics more attractive might result in more teachers becoming certified in
physics. Thus, more schools would have certified physics teachers, and more schools
would be able to offer physics and include advanced-placement physics.

In their article, “Teaching Scientific Reasoning Skills: A Case Study of a

Microcomputer-Based Curriculum,“ Friedler, Nachmias, and Songer (1990) addressed

 

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a major concern of science education and enumerated new ways in which science

education could be improved.

One major concern of science education is preparing students to live in a
rapidly changing society. In order to recognize, address, and shape new
scientific and technological changes, students need not only understanding
of scientific facts from the natural and physical science, but also problem
solving skills. These expert thinking skills do not develop spontaneously.
Science educators must look for ways to encourage and develop such
important inquiry skills in their students. (p. 58)

Bork (1990) suggested the computer as one of the major tools to be used to
solve some of the problems in physics education. He also pointed out that there were

problems in the way we have utilized computers.

We have serious problems in the Ieaming of physics that we are now
currently facing. The computer could be a major tool in overcoming these
problems, but the ways we have used computers so far do not address
these problems nor do anything substantial to improve the Ieaming of
physics. Many current efforts, although well intended, are
counterproductive. (p. 32)

He continued to describe the use of computers in physics today:

Although there is much talk about computers and physics classes, we see
little positive net effect. So far, the computer as a Ieaming device has
made little change in the way courses are being taught. Again there are
exceptions, but most of our courses are still essentially lecture and
textbook-based courses, with only at best minor additions from the
computer. In addition, much of the computer material available in
physics is not of high quality; it lacks even the professional standards that
we see in the poorer textbooks. Most of the material produced so far must
be considered bits and pieces, small individual programs. It makes little
difference in the extensive process of teaching physics. (p. 33)

High quality Ieaming materials for Ieaming physics are lacking. Since the MBL
is of high quality for Ieaming physics, it could fill this void.
To improve the way computers are used in physics, Bork suggested that the effort

in computer usage in Ieaming physics concepts should be experimental.

 

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What has happened so far should be viewed not as serious production of
curriculum material, but rather as an experimental effort, we are trying
out different tactics involving the computer to get some idea of the range
of what is possible. (pp. 33-34)

The ways technology could be used to improve Ieaming science and mathematics
were discussed in the 1989 documents of the American Association for the Advancement
of Science (AAAS) and the National Council of Teachers of Mathematics (NCTM). These
articles indicated that the following topics should receive special attention. (Notice that

ltems two and three involve using computer technology.) The topics are:

1) The use of real-world problems to motivate and apply theory.

2) The use of computer utilities to develop conceptual understanding.

3) Computer-based methods such as successive approximations and
graphing utilities.

4) The use of scientific calculators.

5) The connections among a program situation, its model as a function in
symbolic form, and the graph of that function.

6) Functions that are constructed as models of real-world problems.
(Roth, 1992 p. 307)

Roth recommended that new Ieaming environments, which integrate science,

mathematics, and technology were needed for physics education.

There is one subject that is ideally suited to achieve such an integration of
mathematics, technologY. and science while dealing with real-world
problems-«physics. This fit comes from the fact that physics is rich
in mappings of the real world into mathematical symbols and from here
back into the real world.

In order to achieve such mappings between real and symbolic worlds, and
in order to achieve an integration of science, mathematics, and
technology, new Ieaming environments have to be explored. (p. 307)

Soloway (1994) pointed out that the MBL is one of these potential environments:

Microcomputer-based labs (MBL) are an emerging technology that
provide learners with new ways of seeing--and thinking about--
scientific phenomena. In MBL, student connect up all sorts of probes--
temperature, pH, motion--to a personal computer through a d/a
converter. The data from a probe is pumped straight into a spreadsheet
and graphically displayed on screen in real-time. (p. 15)

 

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The MBL appears to be an environment which achieves an integration of science,
mathematics, and computer technology. In order to investigate the impact of the MBL on

student's Ieaming of physics concepts, this study considered the following specific

multiple perspectives.

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The MBL is a Ieaming environment that needs to be examined from a number of
different viewpoints. This section examines how experts viewed related problems in
student's Ieaming physics concepts, and how scientists link these perspectives to this
study. More literature review to support these multiple perspectives is given in
Chapter two. Multiple perspectives were used to look at different viewpoints and

quantitative viewpoints. This approach lends itself to finding a variety of indicators for

learning physics.

 

In his article, ”Tools for scientific thinking---microcomputer-base
laboratories for physics teaching,“ Thornton (1987) addressed some problems students

had in Ieaming physics concepts:

Traditional science instruction in the US. refined by decades of work, has
been shown to be ineffective in altering student misconceptions and
simplistic understandings. Even at the university level, students--
science majors and not--who take postsecondary physics courses,
continue to hold fundamental misunderstandings of the world about them:
any science Ieaming remains within the classroom context and has no
effect on their thinking about the larger physical world. The
ineffectiveness of these traditional courses is independent of the apparent
skill of the teacher and student performance in such courses does not
depend on whether students have taken physics courses in secondary
school. (p. 230)

In a survey of physics texts, Wilson and Aubrecht (1990) found that:

 

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with over 1000 problems; yet these problems emphasize only a very
limited class of skills. Over 90 percent relate to analytical skills, only a
small number relate to the very important estimation skills, and almost
none expect students to use numerical approaches. Indeed, it is likely that
a student could study physics for eight years without ever seeing a
problem the teacher couldn't solve. We must engage students in the
intellectual process of modern physics much earlier in their training.
The microcomputer can help achieve this by permitting students to
approach a wider variety of phenomena and problems than is possible
with only analytic tools. (p. '46)

According to Thornton, Wilson and Aubrecht (1987), the traditional methods and
content of all texts were working ineffectively in helping students' learn physics'
concepts. They enumerated two problems that students encountered when learning
physics concepts in the traditional way. First, the physics concepts that students
learned in the traditional classroom remained within the classroom context and had no
effect on their thinking about the larger physical world. Second, it was likely that a
student could study physics for eight years without ever seeing a problem the teacher
couldn't solve. The traditional curriculum methods of physics instruction was
ineffective in solving these two problems.

In terms of helping MBL students find phenomena beyond the classroom context
and select problems the teacher couldn't solve, Thornton (1987), discussing the MBL,
concluded that,

Such instruments not only extend the kinds of phenomena that can be
investigated, they also measure phenomena over time-scales that are both
shorter and longer than can ordinarily be conveniently used.
Temperature variations can be measured over days to study diurnal
temperature cycles and whether changes, while sound pressure waves are
easily measured and displayed over milliseconds. (p. 235)

According to Thornton, the MBL has the capability to measure phenomena over

time-scales that could be shortened or lengthened to an extent not ordinarily possible or

convenient. This capability would help students to discover phenomena that were not

 

 

   

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available in the traditional classroom context. Given these capabilities, to what extent

do students learn physics concepts? This is the first foci of this study.

Seiger (1990) addressed the need to develop science research skills in his
article, “IBM's PSL Promotes Hands-On Learning.“
Science is about experimenting, hypothesizing and analyzing. As any
science teacher will tell you, these are not easy skills to teach or learn,
and often the kinds of experiments that can take place in a class-room are
limited by the available equipment. (p. 2)
According to Seiger, students could not easily obtain the needed research skills
(i.e. experimenting, hypothesizing and analyzing) in the traditional approach to Ieaming
physics concepts.
With the PSL, one 384K MS-DOS computer can enable students to perform
sophisticated experiments much faster than is possible using traditional methods. It
seems the PSL has the potential capability to assist students in obtaining the necessary
skills that Seiger suggested.
Thornton (1987), discussing the potential of the MBL, predicted that,
With such tools, students in a beginning science course can form and
verify hypotheses by using the immediate world around them as a
laboratory and by working in a setting in which they can understand and
manipulate data, derived from the physical world, in a personal way. (p.
238)

The second foci of this study is: can the PSL help students develop the needed

skills for future research?

9 'l' SlilllllllSlll
Approximation skills are important for understanding physics. Unfortunately,

they tend to be ignored until advanced studies. Redish (1990) points out:

 

 

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In most versions of the current curriculum, approximation and
numerical skills are left for graduate study, giving most students a
distorted view of physics as an "exact” science, rather than a science
where we know the range of applicability of our equations. This is
particularly unfortunate, since the approach to a complex, open-ended
problem (especially one where the answer is not known beforehand) is
the fundamental skill of the professional scientist. (p. 17)

Redish also proposed that every physics student should have an

opportunity to develop the following six kinds of skills:

1. Number awareness. This is the sine qua non of a physics
major. Students must understand that the universe is
quantifiable.

2. Analytic skills. Students must understand the concept of
equations and be able to manipulate them in reasonably
complex situations. This includes solving problems with up to
a dozen variables, understanding the use of limiting cases, and
formulating strategy and tactics for approaching a complex
problem.

3. Understanding of natural scales and estimation skills. Students
should understand what parameters are responsible for
governing the natural scales of a problem and should be able to
estimate plausible answers and the size of effects to one
significant figure.

4. Approximation skills. Students should understand when an
approximate equation is valid and to what accuracy. They
should have some idea of ways to improve approximations by
variety of techniques.

5. Numerical skills. Students should know how to solve a variety
of problems that are not solvable analytically. Perhaps the two
most important aspects of this skill are knowing what one can
get out of a numerical calculation, and knowing when to do a
numerical calculation and when to do an analytic one.

6. Intuition and large-problem skills. This includes a variety of
metaskills. By intuition we mean having an understanding of when
an answer looks plausible and what to check for. By large-problem-
solving skills we mean such things as chunking (breaking the problem
into parts), mixing library skills with analytic and numerical ones, '
etc. (p. 16)

Wilson (1990) also proposed six skills which are similar to Redish's and which

explained approximation skills as follows:

 

 

 

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Approximation skills. The student should understand when an equation is
being treated approximately and the range of validity of all equations used.
(9- 46)

According to Redish and Wilson, approximation is one of. the fundamental skills
for a professional scientist. It could be one of the ways to alter students' distorted views
of physics as an "exact” science. Unfortunately, this skill involves a great deal of
laborious work to collect data and do complex calculations. Traditionally, students do not
learn approximation skills until graduate study.

The MBL seems to have the capability to help students collect experimental data
easily and accurately and make calculations faster and correctly. Therefore, the MBL
could provide the needed capability for students to learn approximation skills earlier in
their education. The third foci of this study is examination of the specific approximation

skills students gain from the MBL.

Clll' SI'IIIIII'I 'EI'E |
Learning physics concepts is closely related to applying mathematical skills.

Wilson (1990) addressed this relationship as follows:

Selection of topics and indeed the physics sequence itself are largely
determined by the expected mathematical level of the student. (P. 46)

Wilson used the simple pendulum problem as an example to illustrate how

student's mathematical background affected their Ieaming physics concepts.

Consider the case of the simple pendulum. The usual classroom approach
is to write down Newton's second law for a pendulum, make the
approximation of small angles, and then solve the resulting differential
equation for the simple harmonic oscillator. But what happens at large
angles? What happens when a damping force is present? Or what
happens if a driving force is added? The teacher is forced to evade such
questions because the students do not have necessary mathematical
background to consider such complex problems. Further consideration
must be delayed for several years until the students' mathematical skills
develop. (pp. 49-50)

 

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Wilson's example implied that student's mathematical skills needed to be
developed prior to Ieaming physics concepts. Bork (1990) stated that:

We must realize that we cannot solve this problem for physics alone. The
Ieaming problems are too interrelated with othersubject areas; many of
them occur across the educational spectrum.” (p. 37)..."Physics depends
on other subjects such as math." (pp. 37-38)

Were students adequately prepared in mathematics in school? Stipek (1988)

addressed this problem based on several studies of mathematical education.

In Goodlad's (1984) study of over 17,000 young students, math was
rated about the same as reading in a list of "liked" subjects (after art and
physical education). In the National Assessment of Educational Progress,
nine-year-olds ranked math as their best-liked subject; thirteen-year-
olds ranked it second best, and seventeen-year—olds claimed that math
was their least liked subject (Carpenter et al., 1981). Brush (1979)
also shows a decline in positive attitudes toward math in the high school
years. Apparently, children are not born with math anxiety. Rather,
negative attitudes toward math develop over time, especially during
adolescence. (p. 111)

The above studies indicated that students' enthusiasm toward Ieaming
mathematics decreased as they progressed to higher grades. The following studies
explained some of the reasons:

Lazarus (1975) suggests that the cumulative nature of math curricula
(if you fail to understand on operation you are often unable to learn
anything taught beyond that operation) is one explanation. (p. 111)

In an observation study of math and social studies classes, Stodolsky
(1985) found that math instruction had characteristics that would lead
students to perceive their role in Ieaming mathematics as primarily
passive, and to believe that math is something that is learned from an
authority, not figured out on one's own. She found that math classes were
characterized by (1) a reliance on a recitation and seatwork pattern of
instruction, (2) a reliance on teacher presentation of new concepts or
procedures, (3) textbook-centered instruction, (4) textbooks that lacked
developmental or instructional material for concept development, (5)
lack of manipulatives, and (6) lack of social support or small-group
work. The nature of instruction, the behavior expected from students, and
the materials were also more similar from day to day in math than in
social studies classes. This lack of variety may contribute to anxiety
because students who do not do well in the instructional format used in
math are not given opportunities to succeed on alternative formats.
(Stipek, 1988 p. 111)

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These studies indicate that students' mathematical backgrounds were very
inadequate. Negative attitudes toward math have developed through poor educational
processes and led students to perceive their role in Ieaming mathematics as primarily
passive.

However, the MBL environment assists students to perform calculations by
simply choosing the calculation command on a computer without actually performing the
mathematical procedure. This innovation could help students whose mathematical
backgrounds were inadequate. However, this stimulates a new question: Do students
understand the calculation process that takes place when the PSL does all of the
calculations? The impact of the calculation tools within the PSL program is the fourth

foci of this study.

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Sneider and Barber (1990) suggested a way to use computers in teaching science.
In their article “The New Probeware: Science Labs in a Box,“ they state:

The best computer tools for science teaching allow students to use
computers the way scientists do--to collect and analyze data in real time
as an experiment progresses. In this way, students can feel the heat of a
chemical reaction as they watch it being graphed on a computer, 'see' the
sound of a whistle; or watch the distance, velocity, and acceleration of a
cart being graphed when they roll it down a ramp. (p. 32)

According to Sneider and Barber, the MBL provides a new way for students to
understand physics phenomena that they were not able to Ieam in the traditional lab.
This new way of seeing is by using computer graphs to help students perceive science
concepts. Heat, velocity and acceleration are abstract concepts taught to students in
traditional lectures or labs, and many students did not understand these. However, the
PSL program has the capability to display these abstract concepts in graphic form.

Thornton's research on teaching kinematics by using the MBL suggests that this

graphing capability continues to increased understanding:

 

 

 

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12

. . . the lower post-test error rates for students who completed the two
MBL laboratories show significantly improved kinematics understanding.
(p. 864)
McDermott (1990) also conducted a study on teaching kinematics with the MBL.
He inten/iewed 24 students who had experimented with balls and tracks in the
laboratory. They were asked first to describe how they would have to move their bodies
to reproduce the graphs and then to replicate them by moving in front of an MBL motion
detector. He concluded that:
Although eventually almost all the students were able to produce a correct
set of four graphs, observation of their attempts revealed three general
types of difficulties. One fourth of the students initially ignored their
predictions and attempted to produce the desired graph by trial and error,
almost as if they were playing a video game. Sometimes students appeared
not to notice that the graphs they generated did not correspond in detail to
the given graphs. The steepness of a line or shallowness of a curve were
either not considered important or the changes needed to make the graphs
match more closely could not be envisioned. (p. 274)

Thornton's research emphasized the results of the final product (i.e., the post-
test score). McDermott's research emphasized students' approach procedures. Both
researchers found that the visual computer graphs had a positive effect on student
Ieaming of physics concepts. However, their research was limited to college physics
students and to the topic of kinematics. If the MBL were applied to other grade levels or
other topics, to what extent would computer graphs help students understand the
subject-matter knowledge of physics and mathematics? This is the fifth foci of this

study.

Attitudaarmmng
In his book. W191. Wlodkowski (1978)
described how students' attitude affected Ieaming.
Attitudes are powerful. They have pushbutton efficiency with long-term
effects on human behavior. Technically they are the combination of a

perception with a judgment that often results in an emotion that
influences behavior. (p. 36)

 

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"I can't stand English."

"lf I ever have to do another math problem, I'll die."

”Social studies is the living death."

"I love to write.“

“Math really turns me on.“

"This social studies is fun." .

These are common expressions heard in all schools. All of them reflect
an attitude. When students like what they're Ieaming , the classroom is
filled with the two-ism of motivation--optimism and enthusiasm. The '
students are hopeful, cheerful and confident. We are in gear. The mental
set behind the students' perception is to accept, to be involved, and to
persevere.

When students dislike what they're Ieaming, the classroom is filled with
the two-ism of apathy--pessimism and cynicism. (p. 4)

Some literature suggested that technology has some positive impact on a person's
attitude. In the traditional laboratory, some physics instruments were not user-
friendly; they even frustrated students. Thornton (1987) addressed this problem:

A powerful instrument that is difficult to use successfully offers little
pedagogical advantage, especially to the novice science student. The use of
such a tool by a novice often obscures the science behind the data being
collected by focusing the Ieaming on managing the tool instead of Ieaming
the science. An oscilloscope, for example, is a powerful flexible
instrument when used by people familiar with its use yet is too
complicated for novices. The time needed to Ieam to use the oscilloscope
decreases their motivation to investigate and students are often unable to
determine when they are making a satisfactory measurement. Such
experiences contribute to a sense of failure already felt by many students
at a time when they are very vulnerable. (p. 236)

According to Thornton, a non-user-friendly instrument resulted in decreasing
Ieaming motivation and affected Ieaming outcomes.
McDermott (1990) stated that the computer environment had a positive impact
on students' Ieaming attitude:
For some students, the computer provides an environment that is more
comfortable and non threatening than the traditional classroom or lecture
hall. These advantages provide reasons for optimism, but they do not
guarantee improvement in the quality of instruction. There is a need for ‘
research to examine precisely what is occurring intellectually while the
student works at the computer. (p. 279)

The MBL is a computer-based Ieaming environment that could have an impact on

students' Ieaming attitudes. This is the sixth foci of this study.

 

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Concerning the grade levels of students able to use effectively the PSL, research

results in the Technical Education Research Center (TERC) indicated that:

The students could be middle school, high school or college students. The
students might be those interested in becoming physicists or those taking
one of the few science courses they will have during their schooling.
Surprisingly, the motion detector and associated software could be the
same for this wide range of students, although the written curricular
materials would be somewhat different. (Thornton, 1987, p. 230)

Neither of Thornton's articles report how students who had different backgrounds
in computer usage and science education approached the MBL program differently. It is
reasonable to assume, however, that background would influence how one uses the MBL.

Results showed that prior knowledge has an effect on Ieaming.

Gagne and Dick suggested that, 1) newly Ieamed information is
incorporated into existing schemas, 2) recall of previously Ieamed
information is influenced by these schemes, so that remembering is a
constructive act, 3) schemas not only aid retention of new material by
providing frameworks for storage but also alter the new information by
making it 'fit' the expectations built into schemas, 4) schemas allow
learners to make inference that fill in the gaps in stories or expository
prose, 5) schemas are organized not only in terms of figurative verbal
knowledge but also in terms of components of intellectual skills
(operative knowledge), and 6) ideally, learners will became able to not
only to process new information efficiently but also to evaluate and
modify their own schemas. (p. 226)

Good and Brophy (1990) referred to the prior knowledge as schemas and
describes its effects on the learner:
Even when material does not lend itself to interpretation within a well-
developed schema with ready-made slots, prior-knowledge effects will
still occur to the extend that learners can use existing knowledge to
establish a context or construct a schema into with the new information
can be assimilated. (p. 227)

Based on the theory of schemas effect and prior knowledge effect, it is natural to

assume that people from various educational backgrounds might approach the PSL

 

 

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15

differently. If this is true, then instructors should provide various kinds of help for
PSL experiments, based on the students' backgrounds. The seventh foci of this study was
to determine whether students who have both computer skills and subject-matter
knowledge interact with the PSL differently from those who do not have these

backgrounds.

E II I I' 'l .
Based on the observation of how two girls Ieamed physics from a computer

simulation program, Roschelle (1992) concluded that:

The domain of collaboration is diverse and each perspective can offer
valuable insights and tools for analysis. As research about Ieaming as
cognitive and social progresses, it is imperative that differing accounts of
relationships among conceptual change and collaboration are actively
questioned, elaborated, and investigated. The quest for convergence in
what we mean by 'leaming by collaborating' is an essential goal for
Ieaming sciences. (p. 48)

Roschelle's findings raised a question about collaborative Ieaming for students
who are attempting to Ieam physics concepts on a computer. His findings indicated that
collaborative learning improved students' Ieaming physics concepts in various ways .

In ”Workshop Physics: Replacing Lectures with Real Experience,” Laws (1990)
suggested peer Ieaming for students who are Ieaming physics concepts.

Peers are often more helpful than instructors in facilitating original
thinking and problem solving. The time now spent by students passively
listening to lectures is better spent in direct inquiry and discussion with
peers. The role of the instructor is to help create the Ieaming
environment, lead discussions, and engage in Socratic dialogue with
students. (p. 24)

Based on the previous research, Slavin (1985) identified some benefits of

collaborative Ieaming:

 

 

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Cooperative Ieaming programs have positive effects on a wide range of
outcomes, including achievement, intergroup relations, attitudes toward
mainstreamed academically handicapped students, and self-esteem.
(Slavin, 1985 p. 13)
Johnson and Johnson (1984) addressed the need for collaborative Ieaming based
on socialization.
At a time when being able to interact effectively with other people is so
vital in marriages, in families, on jobs, and in committees, schools insist
that students don't talk to each other, don't work together, don't pay
attention to or care about the work of other students--students are
encouraged not to care about students' Ieaming in the classroom. (p. 7)
Johnson and Johnson believed that cooperative learning has a special function in
reinforcing the school's general objectives.
In our schools we can see to it that all of our students work to develop
positive attitudes toward subject areas, such as math and science, so that
students are motivated to study these subjects and to Ieam more about

them. Those who have special aptitudes must be qualified to take advanced
training, so they can possibly enter careers related to science and math.

(0. 7)
Physics experiments often use a team approach. If the PSL supports
collaborative Ieaming, that capability could be used to assist students to Ieam physics

concepts. This is the eighth foci of this study.

When Turkle (1984) interviewed a public school computer teacher, the teacher
confided to her: '
We're sort of keeping it a secret. The teachers don't know. We haven't
figured out all the codes yet, but we're working on it. (p. 99)
This teacher's response reflected teachers' computer readiness in public schools,
readiness which affects their teaching in a computer environment and their attitudes

toward using computers.

17

A study of student teachers by Downes showed that experience with
computers in the classroom and a good role model, in the form of a
classroom teacher who uses computer, lead to more positive attitudes
towards computers and an increased likelihood that the student teachers
would use them in their own teaching. While most studies of teacher
attitudes towards computers have tended to look_ primarily at either
student teachers or Primary teachers, some have shown that computer
literacy courses can improve teachers' attitudes. Madsen and Sebastiani
report several studies showing that the greater proficiency teachers have
with computers the more likely they are to use them and to exhibit less
anxiety towards them. There is also evidence that teachers' positive
attitudes can rub off on the students leading to improved performance.
(Robertson, Calder, Fung, Jones & O'Shea, 1995 p. 73)

Research concerning the teachers' readiness was not the major emphasis in this
study. However, research concerning an investigation as to whether the PSL
improved the computer readiness for teachers, as it relates to students' Ieaming

physics concepts would be valuable.

W
The research foci presented in the previous section are summarized as follows:
1 . To what extent do subjects Ieam physics from the PSL program?
2. What computer skills do subjects gain for future research from
the PSL?
3. What approximation skills do subjects gain (from the PSL?
4. Do subjects understand the calculation process when the PSL does
all of the calculation?
5. To what extent do computer graphs help subjects understand
the subject-matter knowledge of physics and mathematics?

6. Do subjects' attitudes toward the use of computers change as they
obtain computer experience while using the PSL? '

7. Do subjects who have both computer skills and subject-matter
knowledge interact with the PSL differently from those who do not
have both skills and knowledge?

 

 

 

 

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18

Does the PSL support and/or encourage collaborative Ieaming?

Does the PSL improve the computer readiness of a teacher?

5' 'I' [II' S! |

If the MBL program is shown to be effective in Ieaming physics concepts in this

research, then there are four main and distinct ways in which the MBL may be used to

enhance Ieaming physics concepts.

1.

This program can be used by an instructor to demonstrate a particular
physics phenomenon during a lecture. For example, an instructor may
use the MBL to show some physical phenomena beyond the traditional
classroom context and, therefore, stimulate students' thinking about
the larger physical world. (Research foci 1,5 & 9)

The MBL program may provide an arena for different grade levels of
students to develop their professional science research skills and

computer-based calculation skills. (Research foci 2 8 4)

. The MBL provides Ieaming opportunities for students which were

traditionally only offered during graduate study of physics concepts.
This category includes approximation. For example, an instructor
may use the MBL environment to design a guided Mass-Spring
Oscillation experiment; based on experimental data the instructor
could then guide the student to combine Hooke's Law and Newton's
second law and use the Fit-line equation (Least Square Criterion) to
compute the spring's constant. This combination is not available in a
conventional laboratory. In other words, the MBL opens a new arena
for students to develop their creativity. This combination enables
students to repeat their experiments quickly. Students may take this

opportunity to formulate more hypotheses and test them again and

19

again. It provides more opportunities for students to experience how
actual physicists use physics. Through these kind of practices,
students could develop the necessary skills to become successful in
physics courses. (Research foci 3 & 7)

4. The MBL may be used as an environment for collaborative Ieaming,
the understandable computer graphs and immediate feedback may work
as a medium or agent to help students work collaboratively and develop
more positive attitudes toward Ieaming physics concepts. (Research

foci 6 & 8)

QueuiemLAflfihamgrs

- Chapter one states the problems and the research foci.

- Chapter two discusses issues related to the impact of computer technology to the
physics concepts.

- Chapter three describes the methods and procedures used for this study.

- Chapter four presents data which relate to the research foci. The data are then
presented, discussed, demonstrated, and linked to the research questions. Conclusions
are drawn based on discussions of the data. Finally, the research findings are
summarized.

- Chapter five uses the results of the findings to suggest and recommend ways to
use the MBL to improve Ieaming the physics concepts. Questions for further research

are stated.

 

 

 

 

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CHAPTER II

REVIEW OF THE LITERATURE

Susan Ellis (1992), director of staff development for the Greenwich
(Connecticut) Public Schools, has been involved with cooperative Ieaming for over 12
years. She believes that teachers who are comfortable with cooperative Ieaming find
unique uses for whatever tool they use, including computers. She states, ”The reality is
that the computer is a tool, and you can teach collaboratively whatever the medium.“ She
notes that students like the interaction and immediate response of computers. “Assuming
the software is good, computers are very motivating tools. So for somebody who believes
in cooperative Ieaming, an added benefit is'that students are happy engaging in tasks
using the computer.‘'

Hooper (1992) echoed this opinion. “Technology has been used for a long time
with individualized instruction. It has been seen as a way to focus on and diagnose
individual needs and prescribe accordingly.” Hooper says that since children learn
better in small groups, cooperative Ieaming is frequently more effective than Ieaming
on their own. ”I've been asking, 'Can kids Ieam computer-based instruction in
cooperative groups as effectively as they can on their own?‘ In fact, we've found that
they Ieam better in groups“ (p. 18).

Hooper says that research has discovered that the greatest benefit of cooperative
Ieaming comes to those who give help to others. 'In the same way that teachers say they

never really know a subject until they teach it, a student who goes through the process of

20

 

 

 

 

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helping another student on a task must first organize the information in his/her brain.
Individual computer workstations do not afford students this opportunity to help others"
(p. 19).

It is necessary to encourage cooperative Ieaming by using the MBL since, as Ellis
and Hooper state, students team more by discussing experiments with each other than
working by themselves. Many ideas flow between students as they discuss the phenomena
of each experiment. They learn new concepts about physics in greater depth and faster
than they would have had they worked alone.

It was not clear to me when I began this research just how important
collaborative Ieaming was to a teacher. As I observed students and listened to their
questioning each other, I realized that, unless teachers encourage cooperative Ieaming,
much will be lost as classes use the MBL.

This study was undertaken to investigate whether the Microcomputer-Based
Laboratory (MBL) has the potential to shift students' emphasis from laboriously
gathering and plotting data to analyzing data in different ways. If this kind of shift in
Ieaming strategy actually takes place, to what extent does it affect Ieaming physics
concepts?

A review of the literature provided the background for this study, identifying
appropriate trends that were used to document this investigation. The review of
literature was grouped into the following major categories: 1) how people interact with
computers differently; this category provides a context for the research foci which
relate to students' academic backgrounds and students' attitude toward the use of
computers; 2) the role of computer simulation and approximation in Ieaming physics
concepts; this category provides a context for the research foci of approximation; 3)
real-world computer-oriented experiments and their computation; this category
provides a context for the research foci of the calculation process; 4) the role of the MBL

program in Ieaming physics concepts; this category provides a context for the research

 

 

 

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22

foci about learning physics concept, scientific research skills, and developing teacher's
computer readiness; 5) the role of collaborative Ieaming; this category provides a

context for the research foci concerning collaborative learning.

W

This study investigates how people interact with the MBL's program differently.
Turkle (1984), a professor in the Harvard University Graduate School of Education,
received six grants extending over six years for a research project to observe how
people interacted with computers differently. At that time, Turkle did not observe how
people used the MBL program; however, her observation and findings could readily be
compared to this study in order that others might understand how people of various age
levels interact with the MBL program differently.

Through observing and interviewing all levels of the “computer culture,"
including children playing with computer toys, students using computers in classrooms,
video game enthusiasts, home computer owners, virtuoso "hackers“ (members of the
artificial intelligence community and the first generation of people who owned home
computers), professional programmers and artificial intelligence researchers, Turkle
found three stages in people's relationships with computer usage. These stages were
metaphysical, mastery, and identity.

First there is a 'metaphysical' stage: when very young children meet
computers they are concerned with whether the machines thinks, feels,
and is alive. Older children, from age seven or eight on, are less
concerned with speculating about the nature of the world than with
mastering it. For many of them, the first time they stand in front of a
computer they can master is when they play their first video

game ...... these children are all .involved with the question of their own
competence and effectiveness. When they work with computers they don't
want to philosophize, they want to win. The second stage is one of mastery.
In adolescence, experience is polarized around the question of identity, and

the child's relation to the computers become part of a return to reflection,
this time not about the machine but about oneself. (pp. 18-19)

 

 

 

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soft mastery

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23

Turkle also discovered two very different types of approaches taken by children
who succeeded at the same thing, but did not accomplish the task in the same manner.
Each child developed a distinctive style of mastery, styles that could be called "hard and
soft mastery."

Hard mastery is the mastery of the planner, the engineer, soft mastery is
the mastery of the artist: try this, wait for a response, try something
else, let the overall shape emerge from an interaction with the medium. It
is more like a conversation than a monologue. ...... The former (hard
mastery) is a science of the abstract, the later (soft mastery) is a science
of the concrete ...... the soft master works with a set of concrete elements.
While the hard master thinks in terms of global abstractions, the soft

master works on a problem by arranging these elements, working through
new combination. (pp. 104-105)

Watt (1982) found that,

. . . affluent students are thus Ieaming to tell the computer what to do

while less affluent students are Ieaming to do what the computer tells

them. (p. 59)

According to Turkle's findings, children who were under seven years of age were
- in the first stage of computer usage; they were concerned with whether the computers
thought, felt or lived. Those who were seven or eight years of age were in the second
stage; they were involved with their own competencies. When they played computer
games, they wanted to win. Children who were nine or older who worked on the third
stage seemed to verbalize their experiences which lent the observer to know what they
thought. Since all of the subjects in the present study were over nine years of age, they
were probably in Turkle's third category. '

For people of the same age, Turkle found two distinctive styles of mastery: hard
mastery and soft mastery. Hard mastery is a science of the abstract; soft mastery is a
science of the concrete. ”While the hard master thinks in terms of global abstractions,
the soft master works on a problem by arranging these elements, working through new

combinations.“ Watt (1982) also found two kinds of reactions in terms of interacting

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24

with computers: "affluent students are thus Ieaming to tell the computer what to do
while less affluent students are learning to do what the computer tell them."
Turkle and Watt's findings seem to coincide with Gagne's (DATE) Conditions of

Learning.

There are two kinds of Ieaming conditions: internal and external.
lntemal refer to acquisition and storage or prior capabilities that the
learner has acquired that are either essential to or supportive of
subsequent learning. External conditions refer to various way that
instructional events outside the learner function to activate and support
the internal processes of Ieaming. (Aronson & Briggs, 1995, p. 82)

Aronson and Briggs stated that Gagne classified human learning into four
categories or domains: Intellectual skill, motor skill, verbal information, and cognitive

strategy. Gagne also identified five types of intellectual skills:

High-order rule: Generate new rule for solving a problem.

Rule: Demonstrate application of a rule.

Defined concept: Classify objects, events, or states using verbal description or
definitions.

Concrete concept: Identify instances of the concept by pointing to examples.

Discrimination: Discriminate between stimuli that differ along one or more
physical dimensions. (p. 84)

In order for a person to demonstrate the use of a higher-order rule (i.e., by
generating a new rule), the person must have Ieamed various prerequisite rules.
Because a rule is a relationship between two or more concepts, those concepts are
prerequisite to Ieaming the rule of which they are a part. Similarly, defined
concepts often have as referents concrete concepts (6.9., the concept "chair" can
be Ieamed as a definition or as an object that can be physically identified).
Before a concept can be Ieamed, one must be able to make discriminations
between critical attributes. (p. 84)

From Turkle, Watt and Gagne's findings, one may assume that students of
different ages and with different backgrounds would interact with the PSL differently.

One research foci arises from this point:

 

 

 

 

 

  
 

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Ranaweera (1990

 

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25

0 Do subjects who have both computer skills and subject-matter
knowledge interact with the PSL differently from those who do not have
them?

Concerning the computer's impact on people's performance, Turkle (1984)
stated:

While for some children the computer enhances personal growth, for

others it becomes a place to ”get stuck.“ (p. 19)

Turkle's findings disclosed that computer use affected people's attitudes. Other
research reports indicated that people's attitudes toward the use of computers could be
changed through computer training and that these attitude changes affected their use of
computers.

This was carried out by Sanders and Stone who chose five state co-

educational schools to participate in a intervention field test designed to

promote computer use in girls. Three of these schools were experimental
and two control....(p. 190) The results of the one-term field test in

Sander's words: 'exceeded not only our expectations, but our hopes. The

control school with no intervention, had no increase in girls' computer

use during the term. The attention control school, which had received a

workshop for faculty and reminders of the project every two weeks,

registered a 14% increase. The experimental schools, however, with the
workshop, the bi-monthly calls, and The Neuter Computer, increased

girls' computer use on average of 144% over the term. (p. 190)

Stockdale has shown that encouraging female students to attend 'computer

familiarization' workshops resulted in positive change in attitudes to

computer use. (Siann, Macleod, Glissov, and Dumdel, 1990, p. 190)

In order to determine a student's attitude toward using spreadsheet simulations,
Ranaweera (1990) researched a project consisting of student responses in using
spreadsheets. The results were very positive, and students were quick to try out their
newly acquired skills. The spreadsheet simulation allowed students to ask the ”what if'
questions that physics teachers always hope for, such as, "Does the shape seem
reasonable? What if we change a condition? How will it look?" (p.315)

In the book “Motivation and Teaching: A Practical Guide,“ Wlokowski used two

concrete examples to explain how attitude affected human being's behaviors.

 

 

 

 

 

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26

Attitudes are usually based on belief that are learned and that result from
experience. A young child who enters kindergarten sees her/his teacher
for the first time. The teacher is a person who reminds the child of one of
her/his parents. The child loves her/his parents, and, therefore, likes
the teacher and feels safe in her/his company. The child wants to please
the teacher and is motivated to Ieam because of this. On the other hand, a
13-year-old student has heard from a friend that her/his teacher is
mean and unfair. During her/his first class with the teacher, the
teacher, in a matter-of-fact manner, discusses the course and its
requirements. The student judges the teacher's objective style to be cold
and hostile. She/he fears the teacher and wants to drop the class.

Both of these examples reflect attitudes and how they influence behavior.
Attitudes receive much of their power because they help students to make
sense of their world and give cues as to what behavior will be most
effective in dealing with what world. If someone is going to be hostile, it
is in our best interest to be careful of, and even to withdraw from, that
person. (pp. 36-37)

Stipek (1988) identified two kinds of attitudes that resulted in two kinds of

Ieaming outcomes:
In Atkinson's theory, individuals who believe that they are competent at a
task perceive the probability of success as higher and, consequently, are
more likely to approach the task than individuals who believe that they
lack competencies needed to complete the task. (p. 91)
For students who lack confidence in their ability, anxiety can interfere
with Ieaming and with remembering previously Ieaming material. (p.
103)

Keller illustrated a social-Ieaming theory (Lewin, 1935; Hunt & Sullivan,

1974; Rotter, 1972) in Figure 2-1. (p.392)

 

 

 

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Figure 2-1 A model of motivation, performance, and instructional influence
Keller stated that:

...behavior is considered to be a function of the person and the environment:

a = f(P a E) (Keller, 1983 p. 391)

The illustration in Figure 2-1 and the formula which Keller derived stated that

people's behavior was a function of two variables: personal and environmental. One
factor of personal variables is “motives (values)."

In other words, Figure 2-1 and
Keller‘s formula suggested that a person's behavior is related to attitude.

It seemed that Turkle, Sanders, Stone, Stockdale and Ranaweera's findings
supported Keller‘s theory--attitude is one of the independent variables of human

behavior. This suggests that Ieaming outcomes relate to Ieaming attitudes. This

assumption is linked to another focus in this study.

0 Do subjects' attitudes towards the use of a computer change as they get 2

computer experience while using the PSL?

 

 

 

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28

ll: .03. °l°.l3 11-20121039002fl0'l ‘1]1' . . ° 3.0

The third research focus of this study is: Do subjects gain theoretical
approximation skills from the Personal Science Laboratory (IBM's version of MBL).
The difference between simulation and approximation is that the former does not use
real-time experimental data and the latter does.

There are many reports about computer simulation, but this author has not yet
found any reports about approximation. However, as mentioned earlier in Chapter one,
Redish (1990) pointed out:

In most versions of the current curriculum, approximation and numerical
skills are left for graduate study, giving most students a distorted view of
physics as an "exact" science, rather than a science where we know the
range of applicability of our equations. This is particularly unfortunate,
since the approach to a complex, open-ended problem (especially one
where the answer is not known beforehand) is the fundamental skill of the
professional scientist. (p. 17)

In this quote, Redish stated that approximation skills were left for graduate study.
This implied that only graduate students were able to perform approximation. Redish's
statement explained why research reports about approximation were so difficult to find.
This author believes that research on approximation is badly needed. Computer
simulation and approximation in physics have one thing in common--both deal with
calculation. In order to understand the context of this research, it is helpful to look at
related literature about the computer simulation. In this section, the literature review
is about computer simulation and shows how it links to the research foci of
approximation.

Computers have been used to provide models and simulations for physics
education for many years. At present, personal computer (PC) spreadsheets which
incorporate scientific functions and graphic capabilities can adequately deal with many

computational and data processing needs used in physics. These are easy to Ieam, user

friendly, and the requirement to Ieam a programming language is not needed. For

example. it

 

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29

example, Walter (1989) successfully used spreadsheets to simulate the oscillation of a
mass suspended in a viscous liquid. Guglielmino (1989) applied spreadsheet simulation
to an even more complex oscillation problem which demonstrated the Amplitude of Forced
Oscillations.

To pursue the question, "Why are computer simulations important,“ Guglielmino
provided a very interesting and detailed example called "The Variable Mass Rocket
Problem.“ This problem involved solving a second order differential equation that could
not be solved exactly, except in some very special cases such as zero friction and
constant gravity. However, by using a spreadsheet simulation, one could obtain an
approximate answer sufficiently accurate for a solution to the physics problem.

If the simulation can be made more complicated and more realistic by changing
the spreadsheet, it will be possible to include more realistic and stimulating factors.
The simulation then becomes open-ended and the interested student may be motivated to
spend more time learning physics (Guglielmino, 1989).

"Interactive physics' is a typical physics simulation software program. The
following description from W (Knowledge Revolution, 1990)
describes what interactive physics can do.

Interactive physics allows users to create experiments by drawing
objects on the screen. With Interactive physics, a circle drawn on the
screen becomes the bob of a pendulum. A straight line connected to the
bob becomes a rope. Setting this experiment in motion makes the
pendulum swing back and forth on the screen.
Interactive physics lets users adjust physical quantities (such as
mass, friction, elasticity, and gravity) to explore their effect on an
experiment. Meters measure 12 different properties including
velocity, forces, energy. and momentum. Measurements can be
displayed numerically, on a tachometer-like dial, or graphed with a
strip chart. Vector quantities are shown with animated arrows. (p. 1)
When this author began this study, a company called “Knowledge Revolution" had

just marketed a program called “interactive physics ll," version 2.5. In this version,

students were able to enter collected data into the program and run it on a computer to

corpa'e trt

 

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compare the results with those generated by the simulator. Those comparisons with real
world experimental data reflected a new trend of simulation toward approximation. This
innovation in computer simulation is due, in part, to the fact that computer simulation
in physics education creates a Ieaming theory/paradox--physics knowledge versus
commonsense understanding (i.e., students construct their own understandings of
scientific concepts that is not directly compatible with scientific theory; Roschelle,
1992, p. 43).

The following examples show how computer simulation generates a new Ieaming
theory/paradox--physics knowledge versus common sense understanding.

Through observing two high school students, Roschelle found that they used
various metaphors--pulling, hinging and traveling to express the fact that velocity
changes in a dynamic process. Pulling, hinging, and traveling are the students' common
sense understandings of vector addition. Illustrations demonstrating explanations by

using gestures to relate metaphors to a situation are shown below.

 

 

 

 

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Figure 2-2 Carol described how she understood the resultant velocity by
using a metaphor of pulling.

The subjects' conversation is as follows:

D: But what I don't understand is how the lengthening, the position of
the arrow . . .

C: Oh, you know what I think it is ? It's like the line. Fat arrow is the
line of where it smile that down. Like see how that makes this
dotted line. That was the black arrow. It pulls it. (Roschelle,
1992, p. 15)

Figure 2-2 presents illustrations of Carol's statements in relation to her

simultaneous gestures to the computer screen. She developed an explanation for the

configuration by reference to the metaphor of pulling.

 

 

 

As ms;

Fig,

32

The desired trajectorg, a 45 degree bend

velocitg

   
 

 

acceleration

resultant
velocitg 2
As displaged La hels and resultant added 3
The correct solution Three solution attempts

Figure 2-3 From the simulation graphs, the velocity arrows seen pivoting
about its base, Carol used a metaphor of hinging to comprehend
how the direction of trajectory changes.

The following are direct quotes from the subjects.

D: You are saying this [dotted line] is the black arrow?

C: Yeah.

D: And pulls it the other arrow [points to vel with mouse cursor] like

[

C: . . . like on its hinge. It pulls the other arrow on the hinge down
to the tip of the black arrow.

D: Making the line that you see here [gestures to the trajectory after
the 45 degree bend]

0: Right. (p. 19)

 

 

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33

By “on the hinge," Carol implied that the velocity arrow pivots around its base.
By "to the tip of the black arrow," Carol clarified that the outcome of the pulling process
is that the tip of the velocity arrow moves to the place originally indicated by the tip of

the acceleration arrow.

C: Yeah see that's right
I

D: Oh that's perfect.

C: It does, it [vel] travels right along that edge [acc]. So we want it to
new that edge until there. (sets acceleration) Cause that will
make it [vel] come down straight. See it [vel] will travel along
that edge:

D: =Yeah=

C = until it's straight down:

D: :80 but what we didn't realize before
C

: . . . might have to make it a little shorter though. (p. 31)

Carol stated that the tip of velocity ”travels" along the edge formed by the
acceleration vector; this was the third metaphor she used to understand the vector
addition.

Another example of common sense understanding in the computer simulation is
that of Elastic Collisions. Taylor (1993) observed that a student using the PuckLand
simulation program, written in HyperCard, offered his own common sense definition of
momentum as follows:

Well it ( momentum ) is sort of just, er, the force inside them like their
weight and everything going along and then it hits something and the ,
center of gravity like pushes forward and want to go back into the center

again and When it goes back it pulls the person in this case backwards,
like the bounce effect with the ball. (p. 5)

 

   

ah:
Studs w !

 

 

 

 

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34

When this student was asked to describe momentum to another student who hadn't
studied physics, this student described his understanding of momentum as:

Well I don't know the exact term but, um, it is basically one force hitting
like one object hitting another object with force and bouncing off. (p. 5).

Because of the common sense understanding, Flosechelle (1992) argues that,

Students enter science classes with a commonsense understanding of the
physical world that is not directly compatible with scientific theory.
Moreover, science educators and researchers widely hold the view that
students must construct their own understandings of scientific concepts.
Thus, student of science face the task of reconstructing their idiosyncratic
common sense notions of the physical world to converge on the meaning
shared by the scientific community. A large amount of research literature
documents the fact that the students fail to adopt scientific meanings (e. g.,
Ftesnick, 1983; McDermott, 1984; Halhoun & Hestens, 1985 a & b;
Confrey, 199D; Carramazza, McCloskey & Green, 1981; Clement,

1983; Viennot, 1979). Moreover, students' tendencies to diverge from
desired meanings are exceptionally strong in science education. (p. 43)

Now the common sense understanding of physics raises another question, “How
does one determine whether students use formal physics knowledge or apply common
sense understandings to perceive physics concepts and calculation in computer
simulations?“

In a study of challenging models of elastic collisions with a computer simulation,
Taylor and his colleagues (1993) tried to determine whether students were using their
formal physics knowledge or applying a common sense understanding by exploring: 1)
what factors students considered to be important in predicting the motion of the ice-
pucks after impact (i.e., mass, velocity, speed, weight, size); 2) what factors students
cited as important when considering momentum (i.e., mass, velocity, speed, weight,
size); and 3) what percentage of physics terminology students used during interview
session (i.e., speed, force, energy, momentum, mass, power, velocity, acceleration,
friction, heaviness, kinetic energy, potential energy, weight). The results showed that

when asked what was meant by kinetic energy. half the students thought it was some sort

 

 

 

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35

of force which could be stored, while only a quarter of them associated it with movement.
When asked the formula for calculating velocity, only 65% of the students knew that it
was distance divided by time. Sixty-five percent could recite the formula for kinetic
energy and momentum, although many of the subjects thought momentum had “something
to do with“ mass and velocity.

From the literature cited in this section, it is evident that computer simulations
are a very useful tool in physics education. However, computer simulations in physics
provides an additional effect--common sense understanding.

Thornton (1987) recommended the MBL as a tool to correct students' common

sense understanding:

MBL gives students an opportunity to investigate and correct their
'common sense' understandings of science--a necessary step on the way to
building useful physical intuition--by extending the range of
investigations to familiar phenomena. Students have the opportunity to
verify their own intuition and modify their misconceptions. (p. 235)

This is because the MBL provides students real-time experimental data that are

not commonly available to students.

MBL instruments give students the opportunity to explore and quantify
the physical world (using sensors that are not commonly available or
usable by students, particularly in courses in schools and for non-majors
at the university level). Such instruments not only extend the kinds of
phenomena that can be investigated, they also measure phenomena over
time-scales that are both shorter and longer than can ordinarily be
conveniently used. Temperature variations can be measured over days to
study diurnal temperature cycles and weather changes, while sound
pressure waves are easily measured and displayed over milliseconds. (p.
235)

Thornton's recommendation involves dealing with real-time data to correct
students' common sense understandings of science by using the MBL. Dealing with real-

time data requires approximation skills. According to Redish (1990), approximation

skills are important techniques for professional scientists.

 

 

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36

Using the computer permits us to bring in scale analysis and dimensional
analysis, and to: demonstrate approximation techniques and ways of
extracting physics from computer programs. These are all skills that the
professional must know, but that we had little opportunity to teach in
undergraduate courses. (p. 20)

Approximation is one of the foci in this study.

0 What approximation skills do learners gain from the MBL?

 

Students often have difficulty generalizing science instruction to the real world.
These difficulties include 1) generalizing problems encountered in class with more
complex and ambiguous problems found outside of class and 2) applying abstract models
of scientific phenomena to concrete problems. (Lewis, Stern 8 Linn, 1993 p. 45)

To remedy this situation, physics teachers have created many real-world
experiments for their students. Computers are excellent for these kinds of experiments
because timing, periodic accumulation of large amounts of data, and graphical display of
data are necessary for the experiments, and computers handle all very well. Collings and
Greenslade (1989) began using a computer as a laboratory instrument in their
introductory physics courses at Kenyon College in the fall of 1986. From their practice
and experiences, they recommended that the laboratory computer be viewed in the same
way as any other piece of apparatus, (i. e., students need to understand its capabilities
and know how to use it, when appropriate.) After the novelty of using the computer as a
laboratory instrument wears off, students should regard it in the same light as an
oscilloscope or a voltmeter. They need to know the basic principles on which the
instrument operates and how to make it perform properly, but they do not need to know
all the details of its inner workings (pp. 76-84).

The basic considerations for performing experiments with the aid of a computer
are the same regardless of the particular computer and data acquisition system being

used. Three elements involved in most experiment applications are: 1) timing,

 

 

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Ne

Va

Ea

ex

37

typically on the millisecond level; 2) measurements of voltages presented in the
apparatus and conversions to. a digital form (analog-to-digital conversion); and 3)
output, in the form of voltage signals of digital value generated in the computer (digital-
to-analog conversion).

Based upon these considerations, Collings and Greenslade (1989) designed the
following computer-oriented experiments: Kinematics of Constant Acceleration,
Newton's Law of Cooling, Angular Collisions, Simple and Compound Pendula, Heat of
Vaporization of Liquid Nitrogen, Resistance-Capacitance Circuits, Magnetic Field of the
Earth, and Diffraction and Interference Phenomena.

The major drawback was that to perform the above computer-oriented
experiments, students needed to learn computer programming also. In a real-world
computer-oriented experiment, a computer is viewed in the same way as any other piece
of apparatus--that is, a tool. To obtain correct experiment results, students need to
know the computational process in order to write a correct computational program, so
that they could analyze the data they collected from the real-world experiment. In the
-MBL environment, students do not have to Ieam programming in order to analyze the
data because the computer provides the various calculation commands. This new
computer environment, however, raises a new question:

0 Do learners understand the calculation process when the program does
all of the calculation for them?

One research focus addresses this issue.

IIBIIMBI'I 'EI'C I
By the early 19803, TERC (the Technical Education Research Centers, Inc., an
independent nonprofit development group in Cambridge, Massachusetts) developed a

motion-detector. Since then, several versions of MBL have been developed. The MBL

 

 

 

 

    
      

transform
edge
til
teams '5‘
, student. :

tepcns a

lacs-a:

mOllOn w

38

transformed a student laboratory experience by providing experiment inputs, analysis,
and display routines.

What is the impact of the MBL? How can it be used to enhance the teaching and
Ieaming of physics? Can it be used to create a new Ieaming environment so that
students are able to Ieam physics concepts by doing physics on their own? Three
reports about the usage of MBL were found by this researcher. More research is badly
needed on this topic.

One report entitled “Tools for scientific thinking---microcomputer-based
laboratories for physics teaching" by Thornton (1987) identified the following:
A motion unit for middle school students was designed as part of the
Microcomputer-Based Laboratory Project at the Technical Education
Research Centers, a five-year project funded by the National Science
Foundation and primarily concerned with the production, dissemination
and evaluation of MBL materials (hardware, software and curriculum
units) for middle school science. This project is directed by Robert
Tinker, who has been a pioneer in developing the type of MBL instruments
discussed here. (p. 233)
The observational notes of this research showed that students' understanding of
motion was substantial and not easily changed by counter suggestion.
The girls made a velocity graph of a cart that was speeding up. Their
graph correctly showed a positive slope. As they began answering
worksheet questions about the graph. Their classroom teacher came over
and told them that their graph was wrong. 'No, it's not.‘ replied one of the
girls, 'see how it gets faster, that's why the graph keeps going up.‘ 'It
should be Ievel.’ said the teacher. 'No, it shouldn't I' insisted the girls.
'Level would mean that it's going the same speed.‘ The teacher shrugged
his shoulders and walked off. 'We got it right.‘ said one of the girls, and
the others nodded. (p. 234)
In 1987 and 1988, Thornton and Sokoloff (1990) conducted a study at the
University of Oregon and Tufts University under The Tools for Scientific Thinking
project which introduced the MBL at the college level. Their research involved 1500

college and university students in an Introductory Physics Laboratory course. They

reported the results of teaching kinematics by using the MBL.

39

(1) Students focus on the physical world. Students Ieam concepts by
investigating the physical world rather than only manipulating
symbols or discussing abstractions as is common in traditional
courses. However, in this Ieaming environment, action in the
physical world are directly linked to useful abstractions. For
example, students who see the motion of theirpwn bodies and of other
objects displayed graphically in real time learn kinematics
effectively.

(2) Immediate feedback is available. The immediate feedback helps to
make the abstract more concrete. The immediate coupling of the
graphs to the physical phenomena seems to lead the students not only
to understand graphing as a useful scientific symbol system, but also
aids understanding of physical concepts when students are guided to
examine appropriate phenomena. These observations are consistent
with previous studies on a small number of students which suggested
that even a short delay in the display of data in graphical form can
reduce Ieaming.

(3) Collaboration is encouraged. Immediate feedback supports
collaborative learning and collaborative work provides immediate
feedback. Because data are presented in an understandable way,
students can discuss the validity, the meaning, and the implications of
the data with their peers. Learning is also enhanced by encouraging
students to express their predictions and to discuss unexpected
results with their peers. This process appears to be a powerful one
in learning about the students' alternative representations and in
making them aware of them. The process of working collaboratively
is closer to the way scientist actually work.

(4) Powerful tools reduce unnecessary drudgery. Instead of the time-
consuming drudgery usually associated with data collection and
display in the physic laboratory, student time is spent observing
physical phenomena and analyzing and interpreting abstract
presentations of these phenomena (graphs). Students are able to
concentrate more on discovering and understanding scientific
concepts, and critical thinking skills are more easily developed.
Hypothesis development and verification is encouraged by the ease and
rapidity of repeating observations with changed experimental
conditions. Powerful tools allow students to focus on authentic tasks
in ways characteristic of scientists in the workplace. This is not
commonly the case in school environments.

(5) Students understand the specific and familiar before moving to the
more general and abstract. The environment guides students to
understand a specific, familiar (but often more complex)
phenomenon before moving to the consideration of more general and
abstract examples. Most students seem better able to understand
motion when first considering, for example, their own motion (as
complex as It is) as a reference point and then moving on to more
idealized, less familiar (and less complex) motions with more
general applicability such as frictionless motion or simple harmonic
oscillation. Although it is difficulty to abstract simple laws of
physics from a complex, real process, grounding student

 

 

 

 

 

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understanding in the specific and familiar seems to make the abstract
concepts more leamable. Moving from the specific to the general
when investigating new concepts may also be more characteristic of
the scientific workplace than the usual teaching and learning
environment. (p. 866)

Based on their research, Thornton and Sokoloff also pointed out:

The MBL tools give students the opportunity to do real science in the
introductory physics course. Thus students can experience the excitement
of the process of science-—the creative building and testing of models to
explain the world around them. These tools give the science learner
unprecedented power to explore, measure, and Ieam from the physics
world. Because of their ease of use and pedagogical effectiveness, they
make an understanding of physical phenomena more accessible to the naive
science Ieamer and expand the investigations that more advanced students
can understand.

The tools, however, are not enough. Preliminary evidence shows that
while the use of the MBL tools to do traditional physics experiments may
increase the students' interest, such activities do not necessarily improve
student understanding of fundamental physics concepts of the type
discussed in this article. These gains in Ieaming physics concepts appear
to be produced by the combination of the tools and the appropriate
curriculum materials. In general, students improve their understanding
of the physical concepts when they are guided by a curriculum to examine
appropriate phenomena. (Thornton & Sokoloff, 1990, p. 865)

Thornton and Sokoloff's research results indicated that the physics concepts
which the students Ieamed from the PSL were not easily changed by counter suggestions.
It was also important to know that some appropriate curriculum materials were needed
in order to guide them through the examining process of the physical phenomena in the
MBL environment. This indicated that the MBL environment does not guarantee that
students will be able to learn physics automatically. In addition, Thornton and Sokoloff's
articles did not report whether students were able to Ieam physics concepts which were
available without the MBL. Was the MBL able to do this? One research focus is

generated in this context.

0 To what extent do students Ieam physics from the MBL program?

 

 

 

 

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41

The following report was from Xavier University, a participant in the "Tools for
Scientific Thinking" project (Thornton & Sokoloff, 1990). This report could be viewed
as a specific example of Thornton and Sokoloff's research findings at the University of
Oregon and Tufts University.

When Toepker (1993) taught Galileo's Damped Oscillator concepts in his physics
class at Xavier University, he asked his students to do experiments with the following
cylinders: 1) solid aluminum, 2) semirigid core (tomato soup), 3) semiliquid core
(chicken noodle soup), and 4) liquid core (can of soda pop), and then match the
following graphs of displacement versus time on a symmetrical double ramp for the
above four different cylinders.

Figure 2-4 shows four graphs of displacement versus time on a symmetric
double ramp for four different cylinders: noodle soup, soda pop, solid aluminum, tomato

soup.

 

 
 

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0 0.00
0.00 20 .00 40 .00 60.00 0.00 20 .00 40.00 60.00
Time (s) Time (s)

Figure 2-4 Displacement versus time on a symmetric double ramp for four

different cylinders: noodle soup, soda pop, solid aluminum, tomato
soup.

The question he raised with his students was:

Can you match the correct displacement graph with the appropriate

cylinder rolling back and forth on the double ramp? (T oepker, 1993,
p. 538)

The answers were surprising:

When I first started using this experiment in lab last year, I thought
that every student would understand immediately. Well, how wrong I
was I (p. 537)

 

 

 

 

 

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43

What went wrong?

Figure 2-4 illustrates the experiment set up.

Motion Probe

 

 

 

 

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Figure 2-5 The experiment arrangement-Symmetrical double ramp

A motion probe was placed on the left side of double symmetric ramps to record
the displacement of a cylinder. Once a cylinder was made to roll, it rolled back and forth
on the double ramps. As a result, the displacement in this arrangement was always a
positive quantity measured to the right of the detector.

As the aluminum cylinder rolled down the ramp, the velocity and acceleration
were calculated from the displacement which was measured by the motion probe. Figure
2-5 shows velocity versus time for the aluminum cylinder. Note that in the schematic,
velocities to the right were positive and to the left were negative, and the velocity was
zero at the endpoints (highest points reached). This was often confusing to students
because they knew that the displacement was maximum or minimum at the end points.

In order to help his students understand the graphs, Toepker (1993) used a
series of questions/requests to direct the students' attention. See Figure 2-5.

1) Show me from a point on the graph where the cylinder was on one of
the ramps at a particular time. For example, in the following Figure

what point on the double ramp approximately corresponds to each of
the points A through H that are marked on the graphs above the ramp?

 

 

 

 

 

 

 

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data collected 0‘
Students sli/l mar
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44

2) Show, on the velocity-versus-time graph, how to get the acceleration.

3) What would the displacement and velocity graphs look like if the
ramps were not symmetric? For a specific example, what would

happen if the end of one ramp were twice as high as the other? (pp.
5 3 8 - 5 3 9 )

Displacement

 

 

 

-0 .40

030 -0 .60
0.00 20.00 40.00 60.00 0.00 20.00 40.00 60.00

Time (s) Time (s)
Motion Probe

 

 

 

 

 

 

““9 e"-
v_—_>'

(+3,

 

 

 

 

V {-1

Figure 2-6 Displacement and velocity versus time for an aluminum cylinder
on the double ramp. Letter A through H identify points for
students to describe.

Toepker's (1993) teaching experience showed that: even though the experimental
data collected by the MBL were precise and the computer display graphs were obvious,
students still made mistakes in matching the displacements of the cylinders with their
positions on the graphs.

Compare Toepker's (1993) findings with Thornton's (1990) findings, which

were mentioned earlier in this section:

 

 

 

on:

(ion

and

the ill

"33 on

45

The immediate coupling of the graphs to the physical phenomena seems to
lead the students not only to understand graphing as a useful scientific
symbol system, but also aids understanding of physical concepts when
students are guided to examine appropriate phenomena. (Thornton &

Sokoloff, 1990, p. 866)
Their different findings implied that computer graphs assisted students'

understanding physics concepts under certain circumstances. One question should be

asked:

0 To what extent do computer graphs help subjects understand the

subject-matter knowledge of physics and mathematics?

Thornton (1987) also predicted that:

With such tools students in a beginning science course can form and verify
hypotheses by using the immediate world around them as a laboratory and
by working in a setting in which they can understand and manipulate data,
derived from the physical world, in a personal way. (p. 238)

Thornton's prediction implied that MBL had potential capabilities for students
doing research. With assistance from Tinker and Thornton (DATE), Friedler, Nachmias

and Songer (1989) conducted a science experiment within MBL environment.

"The Swimming Pool Investigation,“ confronted the students with a novel
situation in which they acted as swimming pool design consultants.
Students were asked to determine the effect of surface area on the cooling
rate of a swimming pool's water. Prior to performing the experiments
they designed, students made predictions on the cooling rate of two
swimming pools with different surface areas. They drew a prediction

graph and were asked to justify their predictions based on their previous
experiments. ( p. 63)

Although there were no details reported on this experiments, they indicate that
the MBL can be used for students to practice scientific research. The following question

was one of the foci of this study.

 

 

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46

0 What computer skills do Ieamers gain for future research from the

MBL?

The observational notes at TERC (Thornton, 1987) indicated that MBL had an
impact not only on students' learning, but also on the role of teachers in classrooms.
This study focused on the impacts on students' Ieaming. One question related to the
teachers' readiness is also address in this study. That is:

0 Does the MBL improve the computer readiness of teachers?

IbeflolchQollaboLatiyLLsamino
Most educators agree that collaboration enhance Ieaming. As to how computers

might support collaborative learning, O'Mlley and Scanlon (1990) stated that:
When one considers how the computer might support collaborative (as
opposed to individual) activity other roles become appropriate. One
possibility is for the computer to act as a medium for joint activity (eg.
networking); another perspective is that the computer acts as a
cooperative agent in the performance of tasks. A third view is that the

computer is a tool for cooperative activity. These view are not mutually
exclusive. (p. 129)

Thornton and Sokoloff's (1990) findings from MBL research supported O'Malley
& Scanlon's assumption. Thornton and Sokoloff found that the MBL's capability of
presenting data in an understandable way worked as a medium to encourage discussion.
Because data are presented In an understandable way, students can discuss

the validity, the meaning, and the implications of the data with their
peers. (T homton and Sokoloff, 1990, p. 866)

In their book, WNW, Wells & Chang-Wells (1992)

defined collaborative talk and identified some characteristics. They stated that

 

locus

 

47

collaborative talk would help students to achieve specificity in achieving their goals.

There were various strategies that educators might use to guide collaborative talk.

So what is collaborative talk? Conceived quite generally, collaborative
talk Is talk that enables one or more of the participants to achieve a goal as
effectively as possible . . . The occasions for collaborative talk may thus be
very diverse. But what they all have in common is that, at some level of
specificity, one of the participants has a goal that he or she wishes to
achieve and the other participant engages in talk that helps the first to
achieve that goal. (p. 58)

Thus, whether in incidental Ieaming situations in the home or in the more
deliberate situations that teachers arrange in the classroom, the
principles that should guide the adult's participation in collaborative talk
are essentially the same. Adapted from Wells (1986), they can be stated
as follows:

0 Take the child's attempt seriously and treat it as evidence of his or her
best effort to solve the problem unaided.

- Listen carefully to the child's account and request amplification and
clarification as necessary to ensure that you have correctly
understood.

0 In making your response, take the child's account as a starting point
and extend or develop it or encourage the child to do so him- or
herself.

- Select and formulate your contribution in the light of the child's
current manifested ability as well as of your pedagogical intentions,
and modify it, as necessary, in the light of feedback provided by the
child. (p. 59) .

In order to empower Ieaming and achieve the benefits of having two minds

focusing collaboratively, Wells 8 Chang-Wells recommended some strategies:

So far we have looked at collaborative talk in very general terms,
considering the contexts in which it is likely to flourish and the conditions
that must be met if it is to empower Ieaming. Now we wish to examine the
nature of collaborative talk more closely in order to identify those
characteristics that promote the sort of reflective and systematic thinking
on which such Ieaming depends. '-

In order to achieve the benefits of having two minds focusing
collaboratively on a problem, The participants must achieve inter-
subjectlvity in their representation of the task in hand and of their
proposal for dealing with it. Each needs to know the others understanding

48

and intentions, and both must take the appropriate steps to ensure that
mutual understanding is maintained. There is a need, therefore, to be
explicit. Thus, in order to explain the matter in hand sufficiently clearly
for the other participant to make an informed response, each is forced to
construct a more coherent and detailed verbal formulation than would be
necessary if he or she were working on the problem alone. In the process,
gaps and inconsistencies become apparent and can be repaired, with the
result that the problem is seen with greater clarity. (p. 60)

According to Wells & Chang-Wells, participants in collaborative talk need to
know each other's understandings and intentions, and both need to take appropriate steps
to ensure that mutual understanding be maintained in order to achieve the benefits of
having two minds focusing collaboratively on a problem.

In 1982, Yu presented an educational communication model depicting
communication between teacher and student in a conference of Educational
Communication and Technology at South China Normal University. He pointed out that
technology could be used to enhance communication between teacher and student. For
example, a video presentation may help a science teacher visualize his/her idea about

how electricity works so that students understand the abstract concept of electricity. He

used two circles to illustrate the communication between teacher and student.

Teacher

 

Figure 2-7 Teacher-student's communication

These two circles represent a teacher and student's knowledge and experiences.
The overlapped portion represents the teacher and student's common knowledge and

experiences indicating that they could share their knowledge and experiences and

 

 

hr

at

WI

49

communicate with each other. The bigger the overlapped portion that teacher and student
had, the more they were able to communicate with each other. Educational technology
could be applied in order to enhance their communication. It is possible that the more
the teacher and the student communicate with each other, the more common knowledge
and experiences they will receive. Therefore, the overlapped portion of teacher and
student's common knowledge and experiences becomes enlarged (Yu, 1982). According
to Yu, the communication between teacher and student relates to their prior knowledge
and experiences.

Applying Yu's educational communication model to students who Ieam physics by

working together in the PSL environment, the model could be changed as follows:

 

Figure 2-8 Student-student collaborative learning

These two circles represent two students' knowledge and experiences. The
overlapped portion is the subjects' common knowledge and experiences.

According to Wells & Chang-Wells (1992) and Yu (1982), the benefits of
having two minds focusing collaboratively relate to several factors. These factors
include relational systematic thinking as well as subjects achieving intersubjectivity in
their representations of a task.

In Thornton and Sokoloff's (1990) research, they concluded that collaboration is

encouraged. Notice that Thornton and Sokoloff's research population was college and

50

university students who took the same physics class, an introductory physics
laboratory, for one year. This suggested that these students knew each other very well
and that the MBL program became familiar to them. They did not report whether
collaboration was encouraged when students worked together with the MBL for a short
time. They also did not report whether the MBL encouraged collaboration for students
who were not college or university physics students. One research focus addressed this
issue.

0 Does the MBL support and / or encourage collaborative Ieaming?

flammflLQLthLLitflaluLLBflififl

According to Turkle's (1984) findings, all the subjects in this study were in the
third age level (9 or 10 years); their performances on the computer programs reflect
their thinking. There were two distinctive styles of mastery: hard mastery and soft
mastery. Applying Turkle's findings will help the reader understand how the subjects in
this study used the MBL program.

Attitude affects a person's performance. Attitudes help students make sense of
their world and give cues as to what behavior will be most effective in dealing with
people and tasks.

The computer simulation is a very useful tool in physics education. However, the
computer simulation in physics has a side effect--common sense understanding.
Thornton (1987) recommended that the MBL could be used as a tool for students “to
investigate and correct their 'common sense' understandings of science.“

This author did not find any reports about approximation. According to Redish
(1990), “approximation“ was left for graduate study in most current curricula; if this >
is true, it explains why it was so difficult to find this kind of research for earlier

education. Research concerning approximation is badly needed.

 

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investigate
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concepts w
till! Ieam St
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Chapter Th1

 

 

__.—_--' “

 

 

51

Thornton and Sokoloff's (1990) research findings and Toepker's (1993)
teaching experience showed that an environment which integrates science, mathematics
and computer technology does not guarantee that students will be able to Ieam physics
automatically. Thornton and Sokoloff's findings indicated that computer graphs assisted
students to understand physics concepts. However, Toepker found that students had
difficulty in understanding computer graphs which were generated from a symmetric
double ramp.

Thornton, Friedler, Nachmias and Songer‘s (1989) findings indicated that the
MBL could be used for a student to practice research.

It is possible to use the MBL to encourage collaborative Ieaming. In order to
empower Ieaming and achieve the benefits of having two minds focusing collaboratively,
some strategies need to be employed. These strategies are to encourage students to
investigate physics' phenomena by achieving intersubjectivity, obtaining relative and
systematic thinking, as well as questioning the reasons for the outcomes.

Therefore, findings indicate that computer graphs are conducive in understanding
- physics better. The MBL with this capability assists students to understand physics
concepts with more clarity. Through the use of graphs and collaborative effort, students
will Ieam strategies needed to understand physics concepts.

The procedures used in this study to investigate the research foci are outlined in

Chapter Three.

 

 

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students I:

learning on:

 

procedures
organized ir
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tools, 6;. s;

and 10) sur

This
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CHAPTER III

DESCRIPTION OF RESEARCH METHODOLOGY

The primary purpose of this study is to determine whether using an MBL shifts a
student's focus to new Ieaming strategies; and, if it does, to what extent does it affect
Ieaming physics concepts. The qualitative method of data collection and analysis
procedures employed in conducting the study is described in this chapter. The chapter is
organized into 10 sections: 1) method chosen for this study, 2) qualitative method
versus quantitative method, 3) validity of the qualitative method, 4) subjects, 5)
tools, 6) site, 7) subjects' activities, 8) data collection, 9) methods of data analysis,

and 10) summary of the chapter.

W

This research used a qualitative method that is “alternatively called
ethnographic, qualitative, participant observational, case study, symbolic
Interactionist, phenomenological, constructivist or interpretive“ (Erickson, 1986).

Ethnography is based on the philosophy of phenomenology, which assumes that
different perspectives of reality are equally valid (Bogdan 8 Biklen, 1982). For
example, consider a situation in which a teacher is being evaluated by a group of
evaluators as he/she teaches a lesson in physics. The first evaluator (e.g., another
teacher) may perceive the situation in terms of the instructional content that the
teacher is conveying; the second evaluator (e.g., an administrator) may see it in terms
of the techniques (teaching strategies) that are being applied; the third evaluator (e.g., a

student) may focus on the teacher's attitude in teaching.

52

persoeC‘.

this class

 

commun".
them. an:

ioectfy tr.

Sir
resea'ch re

population

 

 

quantitative

(Toothalrer

 

Becau:
method the res

data were 00“

were orawn.

 

 

 

53

Ethnographers believe that it is only through identifying these multiple
perspectives that a researcher can adequately describe and analyze what is happening in
this classroom. Consequently, the ethnographer sees the members of a school
community not as subjects, but as informants. The idea is to observe them, listen to
them, and Ieam from them (Spradey, 1980). In other words, ethnographers seek to

identify the categories that informants use to understand their world.

9 I'll' I!!! I}! 9 I'll' ”II I
Since random sampling was not used in the selection of the target group, the
research results of the qualitative method could not be generalized to encompass a large
population. This is the major limitation of the qualitative method. However, the
quantitative method also has its limitations such as Type-l error and Type-ll error
(Toothaker, 1986).
Type I error = rejecting the null hypothesis when it is true
= falsely rejecting null hypothesis
In other words, this is an error, a ”false alarm," when we reject the null
hypothesis when we should have accepted it.
Type ll error = failing to reject null hypothesis when an alternative
hypothesis is true (null hypothesis is false)

= falsely failing to reject a null hypothesis
In other words, this is an error, a “miss.“ (Toothaker, 1986)

Because both methods have their limitations, the issue is not which research
method the researcher used, but rather how he designed the research settings, how the
data were collected, how the analyses of the data were performed, and how conclusions

were drawn.

 

 

 

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health" ’8
sense-qua

translata:

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the respons
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the informa
researcher t

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54

II I! H! [II g H l' I! II !

The enthnographer believes that a study would be valuable as a case study used to
identify factors for consideration. According to Goelz and Lecompte (1984), the
consequence of this fact is that ethnographers must strive for comparability and
translatability:

Comparability requires that the ethnographer delineate the
characteristics of the group studied or constructs generated so clearly
that they can serve as a basis for comparison with other like and unlike
groups. Translatability assumes that research methods, analytic
categories, and characteristics of phenomena and groups are identified so
explicitly that comparisons can be conducted confidently. (p. 22)

The assumption here is that comparisons are carried out by readers and that it is
the responsibility of the researcher to provide the information to make that possible. In
addition, if they desire, readers should be able to replicate the methods of the study from
the information given in the report. This requirement makes it incumbent upon the

researcher to present a full description of the site, the subjects, the role of the

researcher, and the methods of data collection and analysis.

Subjects

Subjects in this study were volunteer students from middle school grades to the
college graduate level and also included one elementary school teacher. Each expressed
an interest in computer-based experiments in science.

The total number of subjects was 23: 4 high school students, 16 middle school
students, 2 graduate students, and 1 elementary school teacher.

In order to recruit volunteers, the researcher received permission from
Michigan State University and Lansing school districts in Michigan. Then Dr. Richard

McLeod who is this author's advisor and committee chair called lots of schools to find

 

 

 

 

students
Mzchlgal‘

Ir
research.
weécame.
science tc
were scie'

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pairs or w:
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allowed “9,8 t

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55

students and teachers. Also this author sent letters through a student organization at
Michigan State University to invite students to participate in this research.

In the letter, the researcher stated, “We need volunteers to participate in this
research. All students from middle school level to the college students level are
welcome. We would particularly like a range of science backgrounds from little or no
science to science major." As a result, some subjects had very little science, and some
were science majors.

The letter also stated, ”The research site will be in your school. You may work in
pairs or work individually, and the time will be arranged at your convenience."
Therefore, some subjects came in pairs and worked together, and some worked

individually.

1991

This research used the IBM Personal Science Laboratory (PSL) program package.
The PSL is a microcomputer-based laboratory designed to help students increase their
understanding of science. The PSL consists of computer hardware and software working
together to provide the science Ieaming experience. The users did not need to know
computer programming in order to use the PSL.

The hardware for the PSL consisted of an IBM computer and four sensors: 1) a
temperature probe used to collect data about temperature, 2) a light probe used to
collect the intensity of light, 3) a pH probe used to collect data about the pH value of a
liquid, and 4) a distance probe that worked like a camera's auto focus sensor to measure
distance.

The PSL software provided menus for users to control the PSL: 1) the main menu ’
allowed users to select existing experiment set-ups or create their own experiment
setups, 2) the run menu allowed users to perform their experiments, and 3) the

analysis menu enabled users to analyze the data in different ways.

Tab“; 3-

 

. ——

Subjec

Subjec

 

Sutjec
Subjec‘
Subject

Subject

 

Subject

 

 

 

 

Subject
Subject
Subject 1

 

Subject l
Subject 1

 

3Ubject 1

SUbject t'
S“blect It

   

S”blect l

  
 

subject 2)

 

Table 3-1 Subjects' general information

56

 

 

 

 

Yearin Taken Taken Taken Computer experience
school phusics chemistrtj other above average below
in school ? in school ? science ? average average
Subject I 11 No Yes Yes X
Subject 2 9 No No Yes X
Subject 3 11 No Yes Yes X
Subject 4 l I Yes Yes Yes X
Subject 5 s No No Yes X
Subject 6 8 No No Yes X
Subject 7 a No No Yes x
Subject 8 8 No No Yes X
Subject 9 8 No No Yes X
Subject to 8 No No Yes X
Subject ll 7 No No Yes X
Subject 12 7 No No Yes X
Subject 13 7 No No “3 X
Subject I4 ? No No Yes X
Subject IS 7 No No Yes X
Subject 16 '2 No No Yes X
X

Subject 1? 7 No No Yes x
Subject 18 7 No No Yes X
Subject 19 7 No No Yes X
Subject 20 7 No No Yes
Subject 21 Grad. Yes Yes Yes X

student
Subject 22 Grad. Yes Yes Yes X

student
Subject 23 Teacher No Yes Yes X

 

 

 

 

 

 

 

 

 

coo! wt
youiet

p‘ne 'lC T'

 

 

 

experrme:
the PSL h

to use the

o.)

The
”mean Sta
°°mDUter lat-
”0 Classes We
Albpenubt c,

The re
“lame lab Ihc
he She/hoof,

dog/79 a door.

 

 

57

A simple example concerning the use of the PSL follows: A hot object tends to
cool when you stop heating it. A cold object taken out of the freezer tends to warm up if
you let it stand at room temperature. These statements seem obvious. To explore the
phenomena more deeply, one may raise questions such as the following: Are all the
objects cooling down or heating up with the same speed? Does the temperature change at
a constant rate? How do factors such as wind, container shape, container materials, etc.,
affect cooling? The experimenters or students could use the temperature probe and the
PSL EXPLORER program to discover facts about how objects cool and warm up. Some
subjects might want to find the relationship between the temperature and time needed.
The software provides graphic displays of the changes for easy analysis.

Some printed materials which guided subjects to perform temperature
experiments through a step-by-step procedure were given to the subjects to accompany
the PSL hardware and software. These printed materials assisted subjects to Ieam how
to use the PSL while they were doing their own investigations. (These are in Appendix

o.)

511%

The research sites were in Lansing school district in Michigan and also at
Michigan State University. The research site that the high school provided was a
computer lab next door to a physics lab. At the time subjects participated in this study,
no classes were going on in that room; therefore, there was no interference. (See
Appendix C for diagram.)

The research site that the middle school provided was part of a science lab. The
science lab included one big room and a small room, and the observation was conducted in.
the small room. Subjects sometimes separated this small room from the science lab by
closing a door. As a result, this room had no interference. (See Appendix C for

diagram.)

 

 

 

was in a

for dag“

 

Th
to Ieam hc
the PSL.
expenmen
Ckeabvny j
form a uni:

All t

continued tc

Levé

 

 

58

The research site that the graduate students chose at Michigan State University
was in a computer lab. This lab was not used for teaching at that time. It was very quiet
in the evening and on weekends, and there was no interference at all. (See Appendix C

for diagram.)

The major subjects' activities were at three levels. The first level was designed
to Ieam how to use the PSL. The second level was designed to promote the application of
the PSL. Promoting application here means that students designed their own
experiments with the PSL. The third level was designed to promote creativity.

Creativity here means that the students were able to combine parts of the experiments [to
form a unique or novel solution to a problem.

All the subjects completed the first level of the experiment. Some subjects

continued to complete the second level and third level of the experiments.

Level one: Learning how to use the PSL
In this level, subjects viewed a ten-minute introductory video of the PSL
first and then followed a step-by-step procedures to complete the
following experiments:
(1) A simple temperature experiment (using an existing
experiment template ).
(2) Creating a temperature experiment (creating a new
experiment template).

(3) Running a two-probe experiment

 

 

 

 

 

Sub.
they Workec
All ;
deb schc
level. The
pamdpants 1

“EMS VGrsit

 

Bogda}

research:

 

59

Level two: Designing the subjects' own experiment
Subjects selected any kind of the PSL probes, such as temperature,
Motion , pH, or light probes, to design their own experiment. They

explored the potential application of the PSL to meet their needs.

Level three: Theoretical approximation and analysis
Subjects used additional computer application programs, for instance,
MS-WORKS spreadsheets, to do theoretical approximation and then found
an equation that represents the data collected; in some cases, they used
different calculation functions to perform more complex analyses of the
experimental data. On this level, subjects were expected to explore and

discover something new to them.

Subjects worked together in pairs or individually. If two subjects came together,
they worked together. If a subject came individually, he/she worked alone.

All participants completed the first level. Four high school students, 5 of 16
middle school students, and the elementary school teacher participated in the second
level. The 2 graduate students successfully completed the third level. All the
participants stated that they enjoyed Ieaming and using the Personal Science Laboratory

(IBM's version of MBL).

maniac
Bogdan and Biklen (1982) identify five major characteristics of qualitative
research:
1. Qualitative research has the natural setting as the direct source of data,
and the research is the key instrument.

2. Qualitative research is descriptive.

 

 

 

 

and how

(for high.
student 5
science I.
were no i
needed in
no control

participant

Sense that

 

6O
3. Qualitative researchers are concerned with process rather than simply
with outcomes or products.
4. Qualitative researchers tend to analyze their data inductively.

5. “Meaning“ is of essential concern to the qualitative approach. (p. 27)

The following is a description of the key characteristics of qualitative research

and how each was implemented in this study.

The observations of this study were conducted in a high school science laboratory
(for high school subjects), a laboratory at Michigan State University (for graduate
student subjects), a middle school science laboratory (for middle school subjects), and a
science laboratory in an elementary school (for an elementary school teacher). There
were no time limits for activities; subjects quit at any time or stayed as long as they
needed in order to complete their experiments. The researcher was an observer and took
no control over students and variables so that he could understand the situation from a
participant's perspective. However, this study was not completely naturalistic in the
sense that an observer was just watching as subjects' performed experiments.
W

The research design, data collection, analysis, and reports were completed by this
researcher (this author). The researcher did his best to recognize and filter out
personal assumptions and biases in order to understand an event from the subject's point
of view. The researcher also collected data on thoughts and feelings during the study.
Finally, the data collected from subjects and the researcher's thoughts and feelings were
considered in analyzing data.

As noted in Chapter one, this study was designed to investigate and assess a

number of questions about the impact of the PSL program on subjects' Ieaming of

6]

physics concepts. In order to gather answers to these questions, the researcher observed
how each subject approached the PSL program, and he interviewed each of them. Due to
the diversity of the subjects, each was interviewed with a set of particular questions
tailored to his or her experiences. Some questions were the same for all subjects. (See
Appendix E.)

The following examples illustrate how the researcher interacted in the role of
observer and interviewer.

For the first level of the subjects' activities, subjects followed the PSL manual
provided by the IBM computer company in order to complete three temperature
experiments. These three experiments used step-by-step procedures. It was assumed
that some subjects would get "stuck“ (have problems performing the tasks) due to some
of the terminology and the gap between sequential steps. The researcher observed how
the subjects gained both computer experience and subject-matter knowledge of physics
by solving the problems.

Upon completion of the first level of activities, the researcher asked some
questions in order to stimulate thinking. Responses to the questions reflected the
subjects' depth of thinking. Examples of questions include, “Does the temperature
increase or decrease when you blow on the probe? Is this different from what you feel
when you blow on your skin? Why? If a person removes both temperature probes (one
in hot water and the other in cold) at the same time (after 10 seconds in the step-by-
step experiment that is entitled 'Running a Two-Probe Experiment“), what happens on
the computer screen? How do you explain these results? Can you formulate a
hypothesis from the computer graphs? How will you test your hypothesis by using the
PSL?‘I

Based upon subjects' responses, the researcher identified the major linkages
among the subjects' responses, their computer experiences, and their in-depth subject-

matter knowledge.

 

 

 

 

.5

probe ..
interview
How are
by use;
function

the cloc—L

 

the sum'

F.
approxur
is the the
used in tiJ
approxima
collected:

program?

 

 

62

At the second level of subjects' activities, for those subjects who use the motion
probe to perform a simple pendulum experiment, the researcher asked some follow-up
interviewing questions such as, "What factors affect the period of the simple pendulum?
How are you going to figure out the relationship between the period and the other factors
by using the PSL? What do the new computer graphs mean when you choose a calculation
function in the PSL? Why can a simple pendulum be used to make a pendulum clock? It
the clock goes faster in the winter, how will you adjust it? If the clock goes slower in
the summer, how will you adjust it?“

For the third level of subjects' activities, if a subject performed a theoretical
approximation, the following questions were asked for the follow-up interview, “What
is the theoretical. foundation of this approximation? Could you state the strategy that you
used in finding the approximation equation this way? Do you feel confident that the
approximation equation you obtained adequately represents the real-time data you had
collected? Why? Do you feel confident when you use the calculations in the PSL

program?"

The second characteristic of the qualitative research that Bogdan & Biklen
(1982) identified was descriptive. Verbal descriptions were the major medium for
capturing subjects' behaviors and perceptions as they experienced each experiment.
Graphs were used when verbal descriptions were not enough to capture subjects'
behaviors and perceptions. Numbers such as percentages were used primarily to
support descriptions of events and behaviors.

The major concern of this researcher was the process rather than outcomes or
product: Many qualitative studies have demonstrated that focusing on process can
generate an understanding of how the outcome occurs (Bogdan & Biklen, 1982). This

study did not include any paper-and-pen examinations, and subjects did not have time-

 

 

 

 

limts iC
other W
they COL
researc.’
completél
and how

method t

subjects

[Lam
ti
suited to
Quantltatr‘.
students :
research f
UP' apprca

among SUE

Fina

primary l0c

 

SUDjects th;
role of the I
reporter, H
drCUHlstancl
not efleq lh

sChOOI SubJ‘e

63

limits to complete their tasks. The approach to the PSL was an open-ended process. In
other words, subjects could do what they were able to do with the PSL environment, and
they could do as much as they were able to do. During the observation times, the
researcher focused on how subjects approached the PSL, what kinds of tasks they
completed, what new phenomena they discovered, why they used particular approaches,
and how their attitudes might have changed. This study did not compare the traditional
method of Ieaming in terms of how much subjects' scores changed and which methods

subjects used to Ieam faster.

W

The fourth characteristic of qualitative research, analyzing data inductively, was
suited to this study. This researcher felt that previous research on the MBL used a
quantitative method and measured final scores (i.e., emphasized how the MBL improved
students' Ieaming specific physics concepts) and did not generate a theory to predict the
research foci, which were emphasized on the processes in this study. Instead, a ”bottom
up" approach like inductive reasoning would help this researcher to identify linkages

among subjects.

MearnnngLasQLEssentiaLQanem

Finally, the fifth characteristic, a major concern with ”meaning,” was the
primary focus in this study. The researcher was interested in understanding how
subjects thought and understood the experimental results. As mentioned earlier, the
role of the researcher in this study was as an observer, interviewer, analyst, and
reporter. He was not a helper, nor was he an instructor. However, under some
circumstances, in order to understand "meaning,” clues were provided, if those clues did
not effect the research results. For example, the researcher provided a clue to middle

school subjects so that they could answer the pendulum clock questions, “If the clock goes

 

 

 

taster 1‘

summe-

 

student:
were co
making
making
queshon
period ar
temperatt
reasoning
The secor
heat expa
these Mcl
'meaning'
results or
longer or
Understand
experiment

had diliicul

 

penduIUm.

findings to q

SiUdems_ F

 

  
   

Asd

approach ar.
the data CO“

The

64

faster in the Winter, how do you adjust it?" and "If the clock goes slower in the
summer, how do you adjust it?“ This was because the five subjects of middle school
students were not able to make a connection between period and temperature when they
were confronted with these two questions. However, subjects who had difficulty in
making a connection between period and temperature were not necessarily incapable of
making a connection between the period and the length of the pendulum. These two
questions involved three different reasoning processes: 1) making a connection between
period and pendulum length, 2) making a connection between pendulum length and
temperature and 3) making a connection between period and temperature. The first
reasoning process indicated whether the subjects understood the experimental results.
The second reasoning process indicated whether the subjects had prior knowledge with
heat expansion. The third reasoning process involved the subjects' ability to combine
these two physics concepts to arrive at a conclusion. In order to investigate the
"meaning” of whether the five middle school students understood the experimental
results or other reasons, the researcher provided a clue, "Will the pendulum become
longer or shorter when the temperature is higher?“ This clue helped the researcher
understand the “meaning“ that these five middle school students understood the
experimental results: the longer the pendulum, the longer the period. However, they
had difficulty in making the connection between the temperature and the period of a
pendulum. This did not mean that they were not able to apply the experimental results to
answer the questions. It only indicated that their ability to link the experimental
findings to prior knowledge like heat expansion was different than those of high school
students.

As demonstrated above, Bogdan & Biklen's five characteristics of the qualitative
approach are suited to this study. This study applies these five characteristics to guide
the data collection.

The specific methods used in data collection for this research are as follows.

1.314351

 

 

questc‘

record?“

fl
\.
M

surprisr

 

 

65

All the subjects were asked to complete a survey questionnaire which included

questions about their prior computer experiences and their subject-matter knowledge.

The major data collection techniques were observation, note taking, cassette tape

recordings, and interviews.

Subjects were encouraged to reflect on their activities by writing notes about

surprising results and how the experiments relate to their own experiences.

W

Tesch (1990) identified ten principles and practices of qualitative analysis:

10.

. Analysis is not the last phase in the research process; it is concurrent

with data collection or cyclic.
The analysis process is systematic and comprehensive, but not rigid.

Attending to data includes a reflective activity that results in a set of
analytical notes that guide the process.

Data are 'segmented' i.e., divided into relevant and meaningful 'units.‘

The data segments are categorized according to an organizing system
that is predominantly derived from the data themselves.

The main intellectual tool is comparison.

Categories for sorting segments are tentative and preliminary in the
beginning; they remain flexible.

Manipulating qualitative data is an eclectic activity; there is no one
'right' way.

The procedures are neither 'scientific' nor 'mechanistic.‘

The result of the analysis is some higher-level synthesis. (T each,
1990 p. 95)

Tesch's ten principles were used as an umbrella to cover the data analysis

process in this study. The specific procedures were as follows:

 

 

 

 

when i
Comme

a comp!

(I)

categorie
the data.
Tesch's j
two aspe
vertical c;
had made

were apgf

at

The

Codes Whlc

 

66

Step 1: Review the data

The data analysis began as soon as this study started. Throughout the study, hand
written field notes from observations and audio tapes were processed into a computer.
Comments on each subject and comparisons with other subjects were also processed into

a computer.

Step 2: Identify key linkages

The collected data were repeatedly read to search for possible trends or
categories. "Relevant“ and "meaningful" were two major considerations in organizing
the data. The main intellectual tool to identify key linkages was "comparison." Applying
Tesch's sixth principle in this study, this researcher compared the data of subjects in
two aspects: 1) horizontal comparison (i.e., comparing one subject with the others), 2)
vertical comparison (i.e., comparing subjects with themselves to see what progress they
had made). In some situations, the combination of horizontal and vertical comparison

were applied.

Step 3: Formulated, tested and revised assertions
The initial insights which were formulated in step two were then turned into

codes which were applied to the data. Codes that did not seem to fit were. modified.

Step 4: Write a report--this dissertation

This step consists of a comprehensive review and comparison of all data collected
in this study. Then the findings were generated. For example, in order to determine to
what extent the subjects Ieamed physics concepts, the researcher reviewed all data,
such as the completed survey questionnaires, observation notes, audio tapes
transcriptions, and interview notes. Then he compared all subjects' responses and their

performances in order to ascertain to what extent subjects understood the experimental

 

 

 

resufis

drawn I
resear:
queshC'

subject:

MBLpn

megapb

 

 

67

results and what further reaction they had. Based on this data analysis, findings were
drawn. I

Because this study included 23 subjects, 3 levels of subjects' activities and 9
research questions, the organization of the data report emphasized each research
question. Under each research question, each subject's data were presented by level of

subjects' activities.

Wheeler
The qualitative method was used in this study in order to assess the impact of the
MBL program on physics concepts and to determine whether it had the potential to bridge
the gap between academic Ieaming and real life.

The data are presented in Chapter four.

 

 

V.’

school. 1
study. in
students
1993 an:
Table 4n|
sUltll'ects i

Th
may be hej
Much like

SlUdents n

 

CHAPTER IV
DATA PRESENTATION, DISCUSSION AND FINDINGS

Won

This study took place at one high school, one middle school, one elementary
school, and at Michigan State University. Twenty-three subjects participated in this
study, including four high school students, sixteen middle school students, two graduate
students, and one elementary school teacher. The data were collected between November
1993 and March 1994. There were three levels of subject activities in this study.
Table 4-1 summarizes their purposes, describes the activities, and identifies how many
subjects were at each level.

Throughout this chapter, references are made to PSL graphs and PSL tables. It
may be helpful to know that the data collected by PSL proofs are stored in a data table,
much like a student might produce when collecting data using more traditional matters.
At the same time, the PSL software produces a graphical representation of these data.

Students may use the data in either form, table or graph.

68

 

 

 

 

 

 

Level

Level f

 

 

 

 

 

Table 4-1 Fun

69

pose, activities and how many subjects at each level:

 

Purpose

Activities

Number of
subjects

 

Level one

Level two

Level three

Learning how to use the PSL.

Promoting application of
the PSL.

Promoting creativitg.

 

 

 

Subjects were asked to
follow prescribed proced-
ures to complete three
temperature experiments:
1) Simple temperature
experiment.
2) Creating a tempera-
ture experiment.
3) Running a two-probe
experiment.

Subjects chose probes,
designed their experiment
set- ups and performed
experiments on their own.
There were no prescribed
procedures.

Subjects explored the
usage of the PSL as far as
they could for the topic in

 

which theg were interested.

23

12

 

Table 4-2 summarizes who participated at each level and how many experiments

each subject completed at each level.

 

 

 

‘ r
n “ ‘ ‘fll_
“Ilka
i- .

EXP

Level

 

OCI

oral

 

Level t
0 Si

 

 

interviews

SIUdy Was

Ieaming p

meanings

Cor.

Study, and
pleSented b
$9Cll0n OI If

Dre

70

Table 4-2 Experiments, grade level and participation:

 

 

 

 

 

 

Subjects education High Eighth Seventh 43 :2 g
& Subject school grade grade 3 g '5
number students students students g g 3
Experiments 1 2 3 4 5 6 7 8 91011 1213141516171819 20 2122 23:
Level one: a
OSimpletemperature xxxgxxxxxxx x x x x x x x xx x x

experiment. 4O
0 Creatinoatempera- x xxi’x x x x x x x
ture experiment.
0 Runningatwo-probe x xx xx x x x x x x
experiment.
Level two:
0 Simple pendulum x x x x
experiment.
0 Mass-Spring x x x x
experiment.
0 Calculation x x x x
0 PH experiment. x x
Level three:
0 Approximation for x
experimental data.
0 Exploring advanced x
calculation

XXXXXXXXXXX

XXXXXXXXXXX

Was late and left earlg in level one

 

 

 

 

The data presented in this chapter are derived from audio tape transcriptions,
interviews, and observational field notes by the author. The primary purpose of this
study was to investigate the impact of the Microcomputer-Based Laboratory (MBL) on
Ieaming physics concepts as was stated in Chapter one.

Some examples are presented more than once, because they have different
meanings when viewed from different perspectives.

Considering there were 23 subjects and three levels of subject activities in this
study, and the author reverted to the ten research foci listed in Chapter one, the data are
presented by use of these research foci. Each research focus is examined in a separate
section of this chapter. Each section begins with the presentation of the data. It is
followed by a discussion. Based on the data and discussion, findings are made.

The following are the data presentation, discussion, and findings.

 

 

 

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on the

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zen-n ' on n=' 00-2119

In the Simple Temperature Experiment (Appendix D) of level one, all subjects
were asked two questions: 1) Does the temperature increase or decrease when you blow
on the probe? 2) Is this different from what you feel when you blow on your skin?
Why?

Table 4-3 shows how subjects who had not taken physics responded to these two

questions, and Table 44 shows how subjects who had taken physics responded to the

questions.

Table 4-3 Responses from subjects who had not taken physics:

Question I: Does the temperature Question 2: Does this differ from

 

Subject increase or decrease what you feel when
(Year in sch.) when you blow on the you blow on your
probe? skin? Why?

 

Subject 1 It increased slightly but not very Ah, you feel cool when you blow

 

 

(it) much. on your skin ...... basically you
don't have a cool effect.
(He didn't answer why.)
Subject 2 Increases. The temperature in the room is
(9) cold, when blow on it, it gets
higher ......
Subject 3 It increases. When you blow on your skin, it
(I l) is colder.
Why? why?

Maybe because your body
temperature is higher than your
breath, something like this, is
that right? I really don't know
why. It could be ...... Hm, the
probe ...... I don't know ifit has
the same temperature like your

 

 

 

 

 

 

 

 

Table

 

 

Subj‘
Subyr

 

vhf;
SLLJ.I
Subje

~———__
Slime:

Subje:

Subject
Subject
(7.

Subject
3Ubject
(7)

SUDJect
SUblect
(7)

 

SUDJecti

 

 

72

Table 4-3, continued

body. It would be different. I don't
know the exact answer why.

 

 

 

Subject 5 & Subject 5: It went down. when Subject 5: That made the
Subject 6 I blew on it, it went down skin kind of cold.
(8) a little lower than was.
Subject 7 a Subject 7: It decreased. Subject 3= Yes, your bodu's
Subject 8 Subject 8: No, it can go up, temperature is
(3) increased. warmer than the room
Subject 8: Yes. temperature.
. . S ' :Y '
Subject 9 3‘ SUD-1°“ 9 : 1" increased. ubjectl O dfgfeyefii'czwbeacause mu
Subject 10 Subject 10: It increased. skin fem 3001. and
(3) it goes up.
Subject 9: Mn hm.
Subjectl 0: My skin is hot, and

the air is cold.

 

Subject 11 &

Suject 1 1: Increased.

Sujectl lz‘fes, there is a difference

 

Subject 12 when you blow on your skin,
(7) because you feel colder,
but a ...... I am not sure why.
It is warmer in the air but
is cooler in the skin.
30113901 13& Subject 13: From here it Subject 13: I feel cold.
300.1801 14 increased. from there
(7) it decreased.

 

Subject 15&
Subject 16
(7)

Subject 15: Increased.

Subject 15: I feel cold.

 

Subject 1? &
Subject 18
(7)

Subject 18: Decreased.

 

Subject 19 &
Subiect 20
(7)

Subject 20: Increased.

Subject 20: Yes.

 

Subject 23
(Teacher)

 

 

I ncreased.

 

Different. Because of evaporation.

 

 

 

Tanka‘

 

Su

(Year

 

Subj

 

Subjt
(Cradle

 

 

 

 

 

 

Subject
(Graduat

 

 

Thel
graphs thaf

 

73

Table 44 Responses from subjects who had taken physics:

 

Subject

(Year in sch.)

Question 1: Does the temperature
increase or decrease
when you blow on the
probe?

 

Question 2: Does this differ from
what you feel when
'you blow on your
skin? Why?

 

Subject 4
(11)

(Subject 4was supposed to work with Subject 3, but Subject 3
was late and missed this activities.)

 

Subject 21
(Graduate St.)

I nc reased.

There is a difference. This is

because the effect of evaporation.
When I blew on the temperature

probe, the temperature increased
a little bit at the beginning, then it
started decreasing. The same
amount of heat from each blow
might cause less temperature
incease on my hand because my
hand is much bigger than the
temperature probe. In other
words, the temperature increased
so little that my skin was unable
to detect that small temperature
change on my hand.

 

Subject 22
(Graduate St.)

 

 

It increased.

 

The difference is due to the effect
of evaporation.

The temperature only increased
for a short time when I blew on the
temperature probe, then the
temperature started going down.
My skin was probably not
sensitive enough to respond to
this short time change.

 

The subjects answered these two questions based on the real-time computer

graphs that they viewed by using the PSL. Most of the subjects were confronted with a

conflict between their intuitive feeling and the PSL graphs on the computer screen.

Almost all of the subjects stated that when they blew on their skin, it felt cool (it seemed

that the temperature decreased), but when they blew on the temperature probes, the

temperature increased slightly for a short time, then started decreasing. This conflict

 

 

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74

challenged them. Only two of the subjects could immediately suggest a reasonable
answer to explain why this conflict occurred, but most realized that there was a
difference. Since this was a real-time experiment (i.e., the data are being taken as an
experiment progresses, Sneider & Barber 1990), they accepted. the results of the
experiment that the PSL displayed on the computer screen. Since no one suggested that
the computer data were wrong, it seemed as though they trusted both their feelings and
the computer data. Another problem was how to explain this conflict-«the
temperature increased when they blew on the probe, but they felt a coolness when they
blew on their skin. This conflict stimulated their thinking. Subject 3's response was:
”Why? Why? ...... Ah, maybe because your body temperature is higher than your
breath, something like this, is that right? I really don't know why. It could be ...... Hm,
the probe ...... I don‘t know if it has the same temperature like your body. It would be
different. I don't know the exact answer why". She tried to use her past experience to
explain the difference, "maybe because your body temperature is higher than your
breath“, however, she was not satisfied with her explanation. She could not find a
reasonable explanation for this phenomenon.

Subjects who had a physics background (Table 4-4) understood the
contradiction. Subjects 21 and Subject 22 explained the cooling effect on the skin in
terms of the effect of evaporation. They had different assumptions for the temperature
increase when they blew on the temperature probe. Subject 21 said: 'When I blew on
the temperature probe, the temperature increased a little bit at the beginning, then
started to decrease. The same amount of heat from each blowing on my skin might cause
less temperature increase on my hands because my hand is much bigger than the
temperature probe. In other words, the temperature increased so little that my skin
was unable to detect that small temperature change on my hand.“ Subject 22 explained
this difference in terms of the concept of changing rate of the temperature. He stated:

'The temperature only increased for a very short time, when I blew on the temperature

 

 

 

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75

probe, then the temperature started going down. My skin was probably not sensitive
enough to respond to this short time change.“

Subject 23 also explained the cooling effect on the skin as an evaporation process.
He did not try to explain why the temperature increased when he blew on the

temperature probe.

r ri

From the subjects' responses to these questions, it appeared that this simple
experiment created a problem which was more complex than expected. Subjects did not
find reasonable answers to explain the difference between their observation of the
temperature probe and what they felt on their skin. However, it showed that the simple
temperature experiment helped most of the subjects recdgnize a discrepancy (the
temperature increased when they blew on the probe and felt cool when they blew on
their skin) and question, "why." According to Thornton, the process of discovering this
difference is engaging students in the Ieaming process.

Students gain first-hand knowledge of physical phenomena, construct for
themselves the theories necessary to understand the physical world and
formulate their own questions, further engaging them in the learning
process. To alter misconceptions that were first generated by interaction
with the physical world requires additional interaction. (Thornton,
1987)

From their first-hand data of the Simple Temperature Experiment, most of the
subjects formulated their own question-«the temperature increased when they blew on
the probe and it felt cool when they blew on their skin, “why?“ This conflict engaged 8
of the subjects to think about the "why'. Subject 3, Subject 8 and Subject 10 thought
that possibly the body temperature was higher than the room temperature. Subject 21
and Subject 22 concluded that their skin did not feel the temperature increase (as they

blew on their skin) because the temperature increase was too little and too fast to be

detected by their skin. Additional interaction was needed in order to test Subjects 3, 8,

76

10, 21 and 22's hypotheses. It is possible that If there were a teacher present to help

stimulate questions and guide students' subsequent interaction, students could have

provided a correct interpretation of the data.
Although a well designed measurement tool can help, it certainly is not
enough to ensure that science Ieaming takes place, in most situations.
Accompanying curricula (usually printed materials written for
particular age and skill levels) guide students though initial

. investigations and on to their own investigations. In addition, the teacher
using such materials must encourage, or at least not actively discourage,
an inquiry-based approach to science Ieaming. (Thornton, 1987)
The findings from the Simple Temperature Experiment supported Thornton's

suggestion-- further guidance and additional exploration may be necessary to test their

hypotheses in order to assist students to find a reasonable explanation.

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Only 11 of the 23 subjects experimented with level two. Subjects might choose
probes to perform their experiments. Some subjects performed simple pendulum,
Mass-Spring Oscillation and pH experiments. Some subjects only performed the pH
experiment. In total, ten subjects performed the simple pendulum experiment, eight
subjects measured the period of a Mass-Spring Oscillation, nine subjects explored the
calculation functions and two subjects performed the pH experiment. This section deals
first with those who chose the simple pendulum experiment. The measuring results of
the Mass-Spring Oscillation will be reported in research question two. The results of
exploring the calculations will be reported in‘ research question four. Subjects 1 & 2's
approaches in the pH experiment will be discussed under research question seven.
Subjects who performed the simple pendulum experiment were provided some
instruction in order to help them to get better pendulum graphs. Some clues were

provided for middle school subjects to help them make connection between heat

77

expansion and the length of the pendulum. They had difficulty making this connection
without assistance.
Subjects who performed the simple pendulum experiment were expected to

answer the following questions.

a Qustions about the pendulum clock:
. . Question I : Why can a simple pendulum be

 

 

 

 

used to make a pendulum clock?
Question 2: If the clock goes fast in the
Winter, how will you adjust it?
Question 3: lfthe clock goes slow in the
I Summer, how will you adjust it?
Adjusting
screw

Figure 4-1 Question about the pendulum clock

Note: None of the subjects asked whether the pendulum clock was located in a
place where the temperature was constant or whether the material of the pendulum rod
contracted when heated. It then appeared that they accepted the assumptions: 1) the
pendulum clock is in a place where the temperature is lower in the Winter than in the
Summer. 2) the material of the pendulum rod expands when heated.

Table 4-5 (subjects who had not taken physics) and Table 4-6 (subjects who had

taken physics) list their responses after the experiments.

 

 

 

Ta':

 

 

 

78

Table 4-5 Answers from subjects who had not taken physics:

 

 

 

 

 

 

Subject Answered Question 1 Answered Question 2 Answered Question 3
(Year in sch ) correctly? correctly? correctly?
' (Yes or No} {Yes or No) ' (Yes or No)
Subject I Yes Yes Yes
(11)
Subject 3 Yes Yes Yes
(11)
Subject I I Yes Yes Yes
(‘2)
Subject 13& Yes Yes Yes
Subject 14 Yes Yes Yes
(7)
Subject 19& Yes Yes Yes
Subject 20 Yes Yes Yes
(8)
Subject 23 Yes Yes Yes
(Teacher)

 

Table 4-6 Answers from subjects who had taken physics:

 

Subject

Answered Question I

Answered Question 2

Answered Question 3

 

(Graduate St.)

 

 

 

 

(Var in sch) correctly? correctly? correctly?
' (Yes or No) (Yes or No) (Yes or No}
Subject 4 Yes Yes Yes
(11)
Subject 21 Yes Yes Yes
(Graduate St.)
Subject 22 Yes Yes Yes

 

 

 

79

All of the subjects (Note: most of the subjects had not taken a physics class at that
time) were able to answer these three questions correctly. This could be because the
real-time computer graphs, their measurement and their calculations helped them
discover the correct answers. (Research question 2 will provide more detail.)

To perform the simple pendulum experiment, subjects followed an instructional
guide (not required) with the following steps.

1) Set up the experiment as follows

Motion probe

Simple pendulum [ Q

C)
C)

Figure 4-2 Simple pendulum experiment set-up

 

 

 

 

2) Choose an appropriate experiment set-up from the PSL and start the
swing of the simple pendulum.
3) Start collecting data. If the computer screen shows the following

graphs, reduce the swing and start it over.

80

 

 

D Pendulum Distance vs. Time
I; 0.55
t
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e (1111):)..1'111'3.
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1.00 2.00 3.00 4.00
Time
Figure 4-3 Incorrect pendulum wave

4) Repeat step 3 until the computer screen shows graphs similar to the

 

 

following.
D Pendulum Distance vs. Time
1
5 3 it A
f 0'55 I I t I 't r t r t
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1 .00 2.00 3.00 4.00
Time

Figure 4-4 Correct pendulum wave

5) From the computer graphs, find out how long it takes for each swing.
6) Make a new simple pendulum (e.g. half length or quarter length) and

repeat step 3 to step 5.

Note: In order to make a new pendulum, subjects 1, 3 and 4 made a
new pendulum by folding the length of the pendulum. When
subjects 19 and 20 performed the simple pendulum
experiment, they tied a knot on the string (half length, quarter 1
length). The researcher thought that it would be a good idea to

keep the knots on the string in order to compare other subjects'

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81

experiment results. Since that time, all subjects made a new
pendulum by simply hanging knots on the stand (their
experimental results are showed in Table 4-7).

Since this instruction suggested a way for subjects to alter the pendulum lengths,
the interesting observation is not their similarity in experimenting with pendulums of
different lengths. Of greater interest is their similarity in applying the PSL to
accomplish their experiments.

There were commonalties on how each subject approached the simple pendulum
experiment with the PSL.

- Subject 1, and the pair of subjects 3 &4 selected the Distance & Velocity
experiment in a pre defined set-up. Paired subjects 13 &14 and paired subjects 19 &
20 selected Distance vs. Time experiment set-ups. Subjects 11, 21 and 22 created
their own different experiment set-ups. However, all the experiment set-ups that they
selected or created met the needs of their experiments very well (Note: all subjects
Ieamed how to select experiment set-ups or create experiment set-ups from the
Temperature experiment). Their success indicated that each subject was able to choose
or create an appropriate experiment set-up to collect data.

0 Subjects 1, 3, 4, 11, 19, and 20 determined the period of the simple pendulum
by measuring the time interval between two successive peaks from the graphs on the
screen. Subjects 13 and 14 measured the period of the simple pendulum by finding the
time intervals between two adjacent troughs. Their performances in finding the periods
suggested that they realized each sine wave on the computer screen corresponded to one
pendulum swing. Subjects 21, 22 and 23 did not complete the measurements. They
stated that they had prior knowledge about the pendulum and knew how to adjust the
pendulum clock.

0 All subjects in the simple pendulum experiment demonstrated that they were

able to used the Graph command and the arrow key to determine the corresponding time

 

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82

of each peak or trough (Note: In the Temperature experiments, all subjects practiced
using the Graph command and the arrow key to find the exact temperature on the graphs.
For further information, see Appendix D). This suggested that subjects in the second
level were able to apply what they had Ieamed from the first level.

The following examples state some differences concerning how subjects completed
the simple pendulum experiment.
Subject 1 (level two experiment)

Upon completing his simple pendulum experiment, Subject 1 drew the following

conclusions:

The speeds (Distance VS. Time and Velocity VS. Time) are the same, but
ah, like the distance of rope, the different length of rope, the shorter one
is shorter (period), I mean the time, and the wider (the wave) is
longer ...... if the length (of rope) is shorter, the period is shorter (the
researcher asked: Does it mean the pendulum moves fast?) Oh no, (after
he compare the waves) ...... I guess it moved fast.

Subject 3 & Subject 4 (level two experiment)

From the first graphs, Subjects 3 &4 discovered that the period of the pendulum
was 2.10 seconds. To see if the period kept the same time for a short time, they ran the
PSL again to collect another set of data. From the second graphs, they found the period of
the pendulum was 2.00 seconds. Because 2.00 seconds was shorter than 2.10 seconds,
Subject 4 guessed: ”While the pendulum was swinging the amplitude was reducing, so
the pendulum moved faster and faster.“ To test Subject 4's conclusion, they ran the PSL
one more time. From the third graph, they discovered that the period was 2.025
seconds. If Subject 4's first conclusion was correct, the period obtained from the third
measurement should have been less than 2.00 seconds. Since the amplitude was reduced
further, the pendulum should have moved faster. Since Subject 4's first prediction was '
not correct, she made another guess: "We couldn't find the exact points of the peak

deflections from the graphs.“ To find a more accurate way to figure out the period,

Subject 3 explored the computer's top menu. As Subject 3 opened the Table from the top

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83

menu, a window showed the data of Time, Distance and Velocity. Subject 4 tried a new

way to measure the period from the Data Table.

 
      

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Figure 4-5 Subject 4's idea in measuring the pendulum period

From Figure 4-5, Subject 4 found the corresponding time of peak 1 was 1.55

seconds and the time corresponding to peak 2 was 3.65. The time interval between these

two peaks was
3.65 -1.55 = 2.10 ( seconds )

It was interesting to note that their measurement from the graphs was as
accurate as the result they found from the Data Table. Because the results they obtained
.from the data table matched their measurements from the graphs, Subject 4 concluded
that the differences of the time intervals between each of the two peaks were not caused
by measurement errors on the computer graphs. She tried to find other ways to do
further investigations, but she could not think of any another idea at that time.

Subject 11 (level two experiment)

 

 

 

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84

Subject 11's partner was absent, so he completed the second level by himself. He
followed the instruction to experiment with whole length, half length and quarter length
pendulums.

In his first experiment-«using the whole length to make a simple pendulum, he
made two mistakes. One was an observation mistake. He wrote down 8.500 instead of
8.050. Another error was a calculation mistake, 8.050-6.000=1.050 (the correct
answer was 1.950). As a result, the time intervals between each two adjacent peaks
were: 1.95 seconds, 2.50 seconds, 2.025 seconds and 1.050 seconds. If his two errors
had been corrected, the periods would have become: 1.95 seconds, 2.05 seconds, 2.025
seconds and 1.950 seconds. (The conclusion in this experiment should have been: the
time intervals between two adjacent peaks were approximately 2 seconds and were
almost constant.) Due to his mistakes, Subject 11 did not draw a correct conclusion.

In his second experiment---the half length simple pendulum and in his third
experiment-«the quarter length simple pendulum, he did not make any observation or
calculation errors. He concluded correctly that the time intervals between the two
- adjacent peaks were almost constant.

From his third experiment, he concluded that pendulum clocks were not as
accurate as a digital watch because their periods were not exactly the same.

Subject 13 & Subject 14 (level two experiment)

Subjects 13 & 14 measured their periods by finding the time intervals between
two adjacent troughs. (Figure 4-8 provides more details.) These two students only
measured the period of each pendulum and the mass-spring oscillation. They did not
make mistakes and did not explore additional alternatives. They were apparently
satisfied with their results. Their experimental results are presented in Table 4-7

(See Research question two).

85

Subject 19 & Subject 20 (level two experiment)

They worked together. One person moved the arrow and read the time from the
screen and the other person wrote down the time and calculated the period. Their
performance was similar to the two former subjects. Their experimental results are
presented in Table 4-7.

Subjects 21, 22 and 23 had prior experiences in adjusting a pendulum clock.
Subjects 21 and 22, who had Ieamed about the simple pendulum theory in college, were
more interested in pursuing the analytic capabilities of the PSL. Subject 21 will be
discussed under research question three, Subject 22 will be discussed under research

question four and Subject 23 will be discussed under research question nine.

D"lIIS'|El|E'I

All of the subjects used similar methods to measure the period of the Simple
Pendulum (i.e. by finding the time intervals between two adjacent peaks). The PSL
graphs showed the relationship between time and displacement of the oscillation very
clearly. This understandable computer display seemed to assist the subjects to
generalize their ideas in measuring the periods. Subjects 1, 3, 4, 11, 19 and 20
measured the periods by finding the corresponding time of two adjacent peaks. Subjects
13 and 14 measured the periods by finding the corresponding time of two adjacent
troughs. In addition, Subjects 3 & 4 discovered that the data in the Data Table were also
a good way to find the periods. The Graph command and the arrow key provided a
powerful tool for the subjects to measure the periods exactly. As mentioned earlier,
Subjects 3 & 4 found that the periods they measured by using the arrow tool and the
periods they measured by using the Data Table matched very well. These perfect matches
were not coincident. The arrow tool read the exact data points that produced the graph.
However, this capability does not guarantee that a subject is able to locate the peak point.

As this researcher observed how Subjects 3 & 4 measured the corresponding time of

 

 

 

 

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86

each peak, they moved the arrow tool back and forth until they obtained the highest value
of the distance. This measurement suggested that Subjects 3 & 4 understood the
relationship between the peak and the distance.

After the experiments, subjects were given a picture of a. pendulum clock and
were asked three questions: 1) Why can a simple pendulum be used to make a clock? 2)
If the clock goes fast in the Winter, how do you adjust it? 3) If the clock goes slowly in
the Summer, how do you adjust it?

All subjects no matter whether they were high school or middle school students
gave accurate answers to these three questions. In answering question one, a casual look
at the computer graphs showed that each swing of a simple pendulum took almost the
same time. Their subsequent measurements by using the graph's analysis tool proved
that each subject's prediction was accurate. (Figure 4-6 and Table 4-6 provides more
details) In answering question two and question three, the three high school subjects
were able to make a correlation between their experimental results and the heat
expansion. Their experimental results was that the shorter the length of the pendulum,
the shorter the period. The heat expansion in this situation was that a pendulum's length
became shorter when the temperature decreased and vice versa. The five subjects of the
middle school were able to make a connection between period and temperature when they
were asked 'Will the pendulum become longer or shorter when the temperature is
higher?" They answered question two and three correctly. The subjects' answers
signified that both subjects who were from high school and middle school were able to
find the relationship between pendulum length and period--the shorter the length, the
shorter the period. However, their abilities to link the experimental findings to prior
knowledge like heat expansion differed. Middle school students showed that they needed
more help from teachers than did the high school students.

From the observation of the Simple Pendulum experiment, this author found that

high school and middle school students used similar procedures to analyze their

 

 

 

 

 

87

experimental data. They reached the same conclusions and were able to answer questions
about the pendulum clock correctly. This suggests that the middle school students were
able to Ieam the simple pendulum concept such as, period and the relationship between
pendulum length and the period, if appropriate Ieaming materials (e.g. the PSL
program) were available to them. It should be noted that none of the subjects from the
middle school and only one subject from the high school had Ieamed the simple pendulum
concept prior to the PSL experiments. The subjects from the middle school did not know
the terminology, “period“. Therefore, the researcher had to ask the question 'how long
does it take for each swing“ instead of using the word ”periodic." In their answers on
how to adjust a pendulum clock in the Summer or in the Winter, all the subjects
demonstrated that they were able to adjust a pendulum clock: i.e. screw the pendulum up
in the Summer (which shortens the pendulum) and screw the pendulum down in the

Winter (which makes the pendulum longer).

WW
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The temperature and pendulum clock problems are "real-world" problems. The
simple temperature experiment provided a conflict for the subjects' reasoning. Through
the simple pendulum experiment, the subjects understood why a pendulum clock could be
used to regulate the time of a clock and provided appropriate solutions to adjusting the
pendulum clock when it moved too slowly or quickly.

These two experiments involved two types of Ieaming processes. The
temperature experiment was simple, but the phenomena was not simple. It challenged
both the subjects who had physics background and those who did not. About 30% of the
subjects who had no physics background asked, ”Why was there a difference between
what they felt and what they observed?“ Two subjects who had physics background

formulated two assumptions to explain this dilemma. According to Thornton (Thornton,

88

1987), additional interaction is needed and further guidance may be necessary in order
to complete this Ieaming process. In the simple pendulum experiment, the computer
display and measuring tool that the PSL provided help students to discover the time
interval of each swing. The ability to repeat experiments with different pendulum
lengths helped students find the relationship between the length and the resulting period.
Consequently, students were able to answer the three questions about the pendulum clock
correctly. This experiment appeared to be a good Ieaming process. However, the
subjects' abilities to make a connection between experimental results and prior

knowledge differed from the high school to the middle school.

. LeveLIbLee
Only Subject 21 and Subject 22 participated in this level. Their performances

will be discussed under research question three and research question four.

Finding 1: With the help of the PSL and some appropriate printed and video materials
(e.g. Appendix A & D), the subjects in this study, ranging from middle
school students to graduate college level students, were able to explore some
'real world' problems and Ieam physics concepts from real-time
experiments. The simple temperature experiment created a challenging
phenomena for subjects. Some subjects who had no physics background
asked why this challenging phenomena happened. Some subjects who had
physics background formulated two assumptions to explain it. The simple
pendulum experiment helped subjects to discover the time interval of each

swing and the relationship between the period and the pendulum length.

89

B IE'I'IIIIIE ISI'IIDSI'IE'
W

To make laboratories engaging and effective for developing useful

scientific intuition, students need powerful, easy to use, scientific tools
with which to collect physical data and to display them in a manner that
can be manipulated, thought about and remembered. (Thornton, 1987)

All the examples in this section came from level two observations. In level-two
experiments, subjects chose the probes that they wanted and designed their own
experiments. Their exploration and understanding of the experimental results differed.
The following examples show how the PSL allowed subjects to manipulate and analyze the
data. These practices helped subjects use the PSL to do research in a way that is similar

to the practices of professional scientists.

Subject 3 & Subject 4 (level two experiment)

The previous section emphasized what subject-matter knowledge that subjects
Ieamed. Subject 3 and Subject 4's performance in the simple pendulum experiment
also demonstrated how they took advantage of different PSL tools to investigate the period
of a simple pendulum. The following analysis focuses on their use of the research tool.

They began by using the PSL to collect data and found that the period of the
pendulum was 2.10 seconds. (Note: This was their first trial.)

Following this first trial, they ran the PSL again to collect another set of data to
see whether the pendulum kept the Same period after a short time. They found the period
of the pendulum was 2.00 seconds. (Note: This was their second trial.)

When they compared these two results, Subject 4 formulated a hypothesis,
“While the pendulum was swinging, the amplitude was reducing, so the pendulum moved

faster and faster.” (Note: This was subject's first hypothesis.)

 

 

 

 

 

 

90

To test Subject 4's hypothesis, the experiment was run one more time. They
found that the period of the pendulum was 2.025 seconds. Since 2.025 seconds was
greater than 2.00 seconds, Subject 4 discovered that her first hypothesis, "If the
amplitude was reduced, the pendulum would move faster," was not accurate. Subject 4
formulated another hypothesis, “We couldn't find the exact points of the peak deflections
from the graphs.” (Note: The subject formulated a new hypothesis)

To find an accurate way to figure out the period, Subject 3 explored the
computer's top menu. As Subject 3 opened the Table from the top menu, a window
displayed the pop-up data of Time, Distance and Velocity. Subject 4 discovered a new
way to measure the period using the Data Table. The subjects then used the data from the
computer's Table to verify whether they had measured accurately while using the
computer graphs. The results showed that the periods they measured from the computer
graphs and the periods they obtained from the Table matched exactly. This meant that
Subject 4's second hypothesis was incorrect. (Note: Second Test)

After testing their hypotheses twice, the subjects tried to find other hypotheses
to test using the PSL. They could think of no new ideas for further testing at that time.

The total time they spent on this investigation was about 30 minutes.

The research procedure that Subject 3 and Subject 4 applied in the simple
pendulum experiment was not new for high school students, especially for those who had
taken science classes in high school. The questions raised in this example were:

- Would Subject 4 be able to detect the differences among 2.10, 2.00 and 2.025
seconds without the help of the PSLs measuring tools? Subject 4 recalled that when she
performed the simple pendulum experiment in her physics class, she counted 1, 2 ....16
and divided the total time by 16 in order to find the period. The stop watch and the
counting method that Subject 4 used in her physics class did not provide an opportunity

for her to measure the period accurately. The PSL program provided this capability.

91

0 Could Subject 4 formulate the two hypotheses without the help of the PSL at
that time? Subject 4's two hypotheses were achieved based on the accurate measurement
of the time intervals of two adjacent peaks. It was impossible for Subject 4 to find the
difference between the time intervals by using the stop watch she had in her physics
class.

0 Could Subject 3 and Subject 4 complete three trials and two tests in 30
minutes without the help of the PSL at that time? Upon completing the experiments,
Subject 3 said: "It (the PSL) is faster.” and Subject 4 said, "You don't have to write it
down.“ Their responses suggested that the PSL helped them save time in collecting and
analyzing data, so that they could complete three trials in a short time.

Discussion:

Subject 3 and Subject 4 were high school students. Subject 3 had taken
introductory analysis and Subject 4 was taking physics at that time. Subject 4
remembered when she measured the period of a simple pendulum in her physics class,
she counted it 1, 2, 3 ...... 16 and then divided the time by 16. This was the only thing
- she explored in her regular physics class. This time, she used the PSL to explore the
simple pendulum in greater depth than she had in her physics class. Since the motion
probe was very sensitive (six significant digits), the data she and Subject 3 collected
showed differences among the periods after two trials. She formulated two hypotheses
and tested them. Her approach was: Try-«try again---formulate a hypothesis---test
the hypothesis-«formulate a new hypothesis, and then test the new hypothesis again,
the same approach used by professional scientists.

It was interesting that these two subjects were stimulated by the notion of
research and wanted to test additional hypotheses. The differences between these two .
subjects and the other grade school subjects were that Subject 3 was the only high school
subject who took Introductory Analysis and Subject 4 was the only high school subject

who took physics.

92

Subjects 1, 3, 4, 11, 13, 14, 19, 20 (level two experiment)

It was interesting to observe that all subjects used similar ways to determine the
periods. The procedure they used to determine the period was to: 1) use the PSL to
collect the data, 2) move the arrow to find the corresponding time of each peak, 3)
calculate the time intervals between the two adjacent peaks(or troughs), and 4) make an
approximation for the periods. As mentioned in the previous section, all subjects in the
pendulum experiment were provided instructions on how to get a correct pendulum
graph. This provision was based on the fact that this researcher asked five people who
were not subjects in this study to try the PSL program. These five people had difficulty
in obtaining a‘ correct pendulum graph. With the help of given instruction, none of the
subjects in the pendulum experiment had trouble in obtaining a correct pendulum
graph. As a result, the instructor gave the subjects the needed direction in order to
perform the pendulum experiment. The interested result was not that their general
directions were similar. The interesting result was that their specific procedures in
accomplishing their tasks were similar. For examples:

0 In order to use the PSL to collect data, some subjects selected the Distance &
Velocity set-up, some subjects chose Distance vs. Time set-up, some subjects created
their own experiment set-ups to meet their needs. No one selected Temperature vs.
Time or other experiment set-ups to collect the data in the pendulum experiment. It
appeared that all subjects in performing the pendulum experiment were able to apply
the knowledge they had Ieamed in level one. They were able to select or created an
appropriate experiment set-up to collect data.

- When subjects performed the pendulum experiment, everyone demonstrated
that they were able to apply the arrow tool to find the corresponding time of each peaks.
All subjects practiced using the arrow tool to find the values of points on a graph (see
Appendix D). Their performance in the pendulum experiment showed that they were

able to apply this data analysis tool to a new situation.

93

- Subjects who performed the pendulum experiment to calculate the time
intervals between two adjacent peaks (or troughs) demonstrated that they understood
that one sine wave on the computer screen represented one swing of the pendulum. Their
similar performances implied that subjects doing the pendulum experiment were able to

apply the available tools that they had Ieamed in the first level to a new experiment.

By using the PSL to find the period of a pendulum, Subject 19 and Subject 20's
approach was typical:

In the first experiment, whole length pendulum, they used the PSL to collect data
and record the data as follows:

Distance A vs Ti me

P
01
D
II
q

First, they moved the arrow to
this point and wrote down its
ti me, t = 0.4 (second).

Second, they moved the arrow to
the second peak and wrote down
its time, t = 2.4 (seconds).

Third, they moved the arrow to
the third peak and wrote down
the time, t = 4.5 (seconds).

I
1
1
l
1 Fourth, they moved the arrow to
j the fourth peak and wrote down

I

1

l

I

1

l

t

3' 00:0! FO'UI-“O
P
.b.
«2

 

    

 

the time, t = 6.55 (seconds).

Finally, they moved the arrow to
the fifth peak and wrote down
the time, t = 8.6 (seconds).

5‘ .
— -q-h—-'_

0.4

~
.0

0.00 2.00 4.00 6.00 8.00
Time

Figure 4-6 Subject 19 & Subject 20's Whole length simple pendulum data

Based on the Figure 4-6 data, they calculated each time interval between two

adjacent peaks. Finally, they made an approximation and determined the period of this

pendulum. The period was approximately two seconds.

94

Translation

I!4*4 = l lengh

 

 

2.4
- .4
2
.4 - 2.400
4.500 - 6.550 _ 2.400
6.550 - 8.600 T
:éTheu wrote down... .yg’gm _ 3.233
:the approximate ' " '3' ' 705-
....gva] U8 ofthe period----- ..........:..... ......... -
.. (:2 3800003). . . . . . ”......6. 556 8 600
, ' " ,W - 6.550
.13 ..... . 8.600 2'05
- . . . . - 6.550
..‘... .................................... 2.050

 

Figure 4-7 Subject 19 & Subject 20's whole length simple pendulum
calculation

Subject 13 and Subject 14 measured the periods by finding the time intervals

between two adjacent troughs.

95

D Dist A vs Ti me

Trough I, t = 1.025 (seconds)
Trough 2, t = 3.075 (seconds)

Trough 3, t = 5.125 (seconds)

 

Trough 4, t = 7.150 (seconds)

 

Trough 5, t = 9.225 (seconds)

 

 

 

0.00 2.00 4.00 6.00 3.00
Time

Figure 4-8 Subject 13 & Subject 14's Long String simple pendulum data

Based on the above data, they calculated each time interval between two adjacent

 

 

 

 

troughs.

, Qflgjml LEW

5 1.0“ 54,,“ tier-3H: - long string 1 length

'3 [.0153 .'.'.I...':3-('>'7"5'.'.I 3 1.0253 3.075 3
33,075 . 420.4,... 3.075 -1.025

3 . 4.050151 .. 2.050,st
55.115. .........71119...........9.125...... 5.125 7.150 9.225
4.14225. 4&1H.;7-_|§.£1-.. .1331; -5.125 -7.150
£3,050“ 31035314. 3.075 213502nd 2950 3rd 2975

Figure 4-9 Subject 13 & Subject 14's Long String simple
pendulum calculation

Table 4-7 summarizes the subjects' experiment results and their procedure.

96

Table 4-7 Summary of the experiments of the Simple Harmonic Motion

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Period of a Period of a Period of a Period Of a Method and
Subject V0018 length 132 length 134 length Mass-Spri 1'19 procedure
(Y . simple simple simple Oscillation used to fj nd
ear 'Il'l sch.) .
pendulum pendulum pendulum the period
(in seconds) (in seconds) (in seconds) (in seconds)
Subject 1 (All the same)
measuring
2331153 23‘ 2.04 (not done) 0.875 1.2 $333
(11th grade) between two
. adjacent
Subject19 peaks.
Subject20 2.00 1.40 1.00 1.2
(8th grade) Procedure:
Collectin
Subjectl 3&1 g
Subjectl 4 2.05 1.45 1.075 1.2 Measuring
(?th grade)
. t 1 1 Recording
3W” 2.025 1.425 1.05 1.2
(7th grade) Calculating
Subject 21
(Graduate Did not complete measurement.
Student)
Subject 22
(Graduate Did not complete measurement.
Student)
(1:113:53 Did not complete measurement.

 

 

Subject 2 did not perform the simple harmonic motion experiment. He chose the
pH probe to measure the pH value of water. His approach will be discussed under
research question eight.

After Subject 21 collected data from the experiments of simple harmonic motion,
he tried the arrow keys on the computer to find the corresponding time of each peak or

trough. He then concentrated on finding equations to represent the data he had obtained.

97

He did not complete the measurement for this experiment. (Further detail is presented
in research question three.)

Subject 22 also tried the computer's arrow keys to find the corresponding time of
each peak or trough. Then he explored the calculation commands that the PSL provided in
order to perform some complex calculation. He did not complete the measurements.
(Further detail is presented in research question four)

Subject 23 participated in level two for only 30 minutes. He explored the usage
of the computer's F4 key (scale graphs) after he collected the data. He did not completed
the measurements. (Further detail is presented in research question ten)

Discussion:

Subjects from middle school and high school used procedures similar to those
professional scientists use, that is: collecting--measuring--recording--calculating. In
other words, the experiences they obtained from the above experiments were authentic

computer research skills.

Subject 11 (level two experiment)
Subject 11's exploration and explanation for the fit-line equation in the PSL

program is illustrated in Figure 4-10 to Figure 4-12 .

TempA = bl*Time + cl

Subject 1 I said this Fit-line represented
those points he marked on the curve.

\/

Figure 4-10 Subject 11's Fit-line Equation-1

)- 1530-1

 

 

 

 

Ti me

98

Temp A = 02*Time + 02

Subject 11 said

the marked points
inside the circle tilted .
the Fit-line up. . '

  
     

b agar-l

 

 

Ti me

Figure 4-11 Subject 11 's Fit-line Equation-2

Temp A = b3*T1'me + 03

h @30—‘1

Subject 1 1 said the marked points inside the
circle tilted the Fit-line down.

J--.
' ‘
I

0"‘5

 

 

 

Ti me

Figure 4-12 Subject 11's Fit-line Equation-3

The Fit-line and its equation raised Subject 11's curiosity. It was a useful tool
for research, but it was beyond the capability of most of the subjects. Subject 11
explored and explained it as follows:

He said the first Fit-line represented the points he marked, the second and the
third Fit-lines did not represent the points he marked because some points changed their
directions.

From his exploration and explanation, it seemed that he had expected to find an .

equation to represent the points he had marked. The first Fit-line equation matched his

99

expectation. He said the first Fit-line represented the points he marked. To further
explore the relationship between the marked points and the Fit-line, he marked other
parts of the curve and obtained two other Fit-lines. Each time that he marked new points
and chose the Fit-line command, the computer gave him immediate feedback; he seemed
to sense that some marked points affected the Fit-line directions. Even though the
directions he pointed to in Figure 4-11 and Figure 4-12 were not accurate (i.e. tilted
up or tilted down), this example showed that the PSL provided the kind of environment
that encourages students to explore and find explanations with immediate feedback.
Subject 11's interaction was only available in the computer environment. Exploring
with the computer program, discovering its potential capabilities and trying to figure
out why something happens in a certain way is a useful way to Ieam computer skills for
future research. The theoretical bases of the Fit-line equation is probably too difficult
for a middle school student to understand. However, the computer graphs and immediate
feedback made a great deal of sense to Subject 11. If a teacher were present to guide him
on how to use the Fit-line, he might have been able to use this research tool effectively.
Subject 11 also took advantage of the computer graphs to find his own calculation
errors. In the Mass-Spring oscillation experiment, Subject 11 had two errors. He
found the errors by comparing the wave on the computer screen with his own calculation
results. Based on the results of his calculation, one of the time intervals was 1.350,
which was much bigger than his other calculations. He wondered why this was so. By
comparing the computer graphs with his calculation procedure, he found that he
mistakenly wrote 2.150 instead of 2.325. He repeated the calculation. Unfortunately
he had another calculation error this time ( 3.500 -2.325 = 1.275, the correct
calculation should have been 3.500 -2.325 = 1.175 ). Subject 11's result was still
inaccurate and only by chance was closer to the correct answer. This example showed
that the comparison of the Mass-Spring wave on the computer screen and his calculation

helped him find that the data did not fit very well; he looked at the data again for

 

I!"
_

100

solutions. When the results were closer to expectations (even though inaccurate), he

was satisfied. The PSL provided Subject 11 with one more tool---computer graphs to

examine his experimental results.

The following figures show how Subject 11 found his observation error and how

he corrected it.

Subject 1 I examined the real-ti me computer graphics

he collected. He found all the time intervals
were almost the same, then he checked
D — — —

_ his calculations.

  
  

t = 9.45 (seconds)

1 = 8.25 (seconds)

 

 

t = 7.050 (seconds)

 

 

t = 5.875 (seconds)

 

t = 4.700 (seconds)

 

 

 

 

 

 

I
l
1 1‘ l: :r‘i t= 3.500(seconds)
l l I: I I
0.47 j it l.’ (j Peak 2, t=2.325(seconds)
i " 'f '1
0,45 . ‘ - Peak 1, t = 1.1 75 (seconds)
0.00 2.00 4.00 6.00 8.00

Figure 4-13 Subject 11's Mass & Spring Oscillation data

101

 

 

 

 

 

 

 

 

   
   

 

0_ri_gjm_t_ Tmnslation
,E ..." ., ...... ...... .f.. . .......---- 1.5
. .i . .. . F1555.” :25; -1.50 -2.55
...54..‘.?0 .. 4.70
43,135 ”5:75 6195 7 ,‘io. -3 6.5 5.75 6.35 7.90
_;| 05“_m—_1-1,'7(‘_j_ S '15 -d;, __9_$ 1.05 -4.70 -5.75 -6.35
s * L05 . “1.1 ”(T—foo 1.05 1.1 1.00
. .. E . . This figure
.. _ Hedtd 1tover.
........!... "15 b—H—q should be 2.325.
31503.1???15 IS 0 4'1 _ St 9‘15 ..—-‘é—. 2325 \

1151 750~ 2 ~§_._§_ ”-1.700 3.500 1.175 5 4.7 5.375
£31355— ' 23 re f. rum-2.325 —1.150 - 0 -3.5 -4.700
.. I n............ u- . .. . .. 1.275 .3 TE W

'1, 05° (3.15 ‘7’"? 7050 325 945
......... “M~--~~----;—-'-IO$0 “717? -5.375 7.050 325
(1'75 173—0 1"- 1.175 120 1.25

The answer should be 1 .175.
( calculation error).

Figure 4-14 Subject 11's errors

In his Mass-Spring experiments, Subject 11 made two errors in the calculation
process. One was that he copied a wrong number from the computer graphs. Another
was a calculation errors. Later he found his errors by comparing his calculation results
with that of the computer graphs. This capability of the PSL was useful for subjects
because the computers stored the data and allowed subjects to examine the data again and
again. Subjects could take advantage of the computer's unique characteristic-memory
to obtain a correct experimental results.

In summary, the PSL allowed subjects to repeat an experiment immediately, do
qualitative analysis (from the graph), quantitative analysis (by using the arrow and the

table), and perform various kinds of calculations. The computer-based characteristics

102

provided subjects with opportunities to quickly explore in depth the experimental data,

test their hypotheses and discover their accuracy or error.

Finding 2: The PSL program enabled subjects to collect data quickly and analyze them
immediately by using the analysis tools. These analysis tools included
computer graphs, data tables and the arrow tool. They helped subjects
measure the pendulum period accurately and analyze the experimental data
very fast. During a short experimental period, subjects were able to spend a
large portion of their time repeating their experiments. By repeating the
experiments and analyzing their data with different tools that the PSL
provided, some subjects formulated hypotheses and tested hypotheses again
and again. Some subjects even found their errors with the help of these
computer analysis tools. This procedure helped subjects experience the

methods that how professional scientists use computers to do research.

‘ :2. 01. O . '32 A |:_ ._I. 0"]. 0| . 00 [0:01 0;. O“ '2 7

Approximation skills. The student should understand when an equation is
being treated approximately and the range of validity of all equations used.
(Wilson, 1990)

In some situations, the data obtained in the experiments were not ideal.
Researchers frequently compute approximations to find an equation which represents
the data they obtain in order to better understand the phenomena.

In this study, only one person, who participated in the third level, was able to do '

approximations.

 

 

 

 

103

Subject 21 (level three experiment)

Subject 21 was a graduate student with a background in engineering and
experience with computers. He was interested in doing approximations to find an
equation to represent the data he collected from the PSL.

The first approximation he completed was the heating curve. He:

1) selected the One-Temperature experiment set-up and changed the
Duration to 15 minutes (the temperature was displayed in Celsius
degrees).

2) measured his body temperature by the temperature probe and

exported the data to MS WORKS spreadsheet.

 

T C 8on Temperature Temperature A vs Time
e W
m36 4 ~. ___,...-_ . .
If
p 36.0 ,. . . .
I;
A 35.6 ,I - - Subject 21 used the
," temperature probe to
35.2 r - - . - masure his bodu
: temperature. After
34.8' ' ' ' ' he collected this data,
. he transferred this
34. 'v -. - -. =- data to a MS WORKS
spreadsheet.
34.0 - . . -
33.6 .- e e 9
33.2 , , : ,
0.00 200.00 400.00 600.00 800.00 (seconds)
Time

Figure 4-15 Subject 21's Body Temperature

104

3) added a column in the MS WORKS spreadsheet.

 

 

        

 

I A a c 0 a
‘2 s . C:

3 0.00000 32 . 20169 1

4 1 .81254 33 .70299 0 .258233 .

_5 3.62500 33 .97560 0 .559318 $20M: °9‘“"‘[:h“’83
6 5.43762 34.19064 0.7354092 “o 9m“ e
,7 7.25017 34.42160 0.6603479 ffrmu'a-

e 9 .06271 34 .59515 0 357253 ' LOG (M)

9 10.67525 34.74365 1 .0364392

am 12 .66779 34 .61620 1.103366

11 14.50033 34.91732 1 .1613???

12 16.31207 35.01645 1 .2125305

13 16.12542 35.06602 1.250260

Figure 4-16 A column with a formula =LOG(A4)

105

4) went back to the PSL , imported the spreadsheet (completed in step 3)

to PSL and opened this new file. These new graphs were displayed:

 

 

 

T C PSL default template Test V8 Time
: ffl-H_ -—
t 2.00 .r" ' ‘ ‘ ‘
I,
{f— The starting point ofthe upper curve is 0.2532.
0.0 - - - -
0.00 200.00 400.00 600.00 000.00 (seconds)
Time
T C PSL default template Temp A vs Ti me
in 36.0 {fa—##fl'T . ‘ .
p {/— The starting point ofthe lower curve is 33.703
r
A 34.0' - r ‘ '

 

0.00 200.00 400.00 600.00 800.00 (seconds)
Time

Figure 4-17 Graph of LOG(A4) vs. experimental graph

Comparing the upper curve and the lower curve, he found that the starting point
was different (i.e. the initial value differed). He:
5) selected the upper graph and looked at the data from the table, he found
that if 33.44 were added to the upper curve, then the upper and the

lower graphs were almost the same.

106

6) used the computers Calculate command to add 33.44 to the upper

graph, then the two graphs became almost the same.

 

 

 

T 0 PSL default template Test vs Ti me
e — . fl
3 36.0 W '
t x"
V—After adding 33.44, the starting point changed to 33.7.
34.0 = 3 a a
0.00 200.00 400.00 600.00 000.00 (seconds) .

Time Note: After 000100 33.44
to the upper curve,
the starting points of

T c PSL default template Temp 4 vs Ti me both curves became

e _,__._.—-—— - — - the same. Comparing

"136-0 f" ‘ ‘ ' ' the upper curve with
z . . . the lower curve,

P {f— The starting point is 33?. Subject 21 found the

A 34 . . . . upper curve increased

faster than the lower

0.00 200.00 400.00 600.00 000.00 {seconds} cum-
Time

 

Figure 4-18 After adding 33.44

107

7) applied the formula LOGbU = LOGaU/LOGab. ( Note: neither the

PSL nor MS WORKS allowed him to use Logarithms with base other

than 10 and 0) He used this formula to keep the base as 10 in order

to construct different approximation curves on MS WORKS and PSL.

In order to find the best one to describe his data, he constructed the

following graphs.

First he used MS WORKS to create a new column with a formula

=LOG(A4)/LOG(9).

=L 03( M }/L03{ 9 )
I

I A

0.00000
1-81254
3.62508
5 .43762
7.25017
9.06271
10.67525
12.68779
14 .5003‘3
16.31287
10.12542
19 -93796

H 6:31-17:30 m VO‘VUI bill N
AuNHO

 

 

5 C

C

LOG9X .NKS

D E

 

33.20169 1

33 .7029? O . 270675313
33.97560 0-5361382
34.19064 0.7706733
34.42160 0.901603
34.59515 1-0031601
34.74305 1.0061302
34.01020 1.1562952
34 .91732 1 .2170679
35 .01645 1 .2706733
35.06602 1.3186249
35.14037 1.3620024

   

He added a new column

with the formula:

=LOG(A4) 000(9)

Note:

L009tn4) =L00(A4)iL00(9}

lfthe new column added
33.44 later, the value in
the new column should
become the same as the
value in the middle
column.

Figure 4-19 A column with a formula =LOG(A4)/LOG(9)

108

Then he exported the above file to PSL and displayed the curves.

  
    

 

 

T C PS L default template Test vs Ti me
e d____,_,__—-—'—"—‘
8 f
t 2-00 ‘ ' ‘ The shape of both the upper
The starting point is 0.2706733. 3"" “we" mm” are
.{ almost the same now.
0'0 ......'...II. 'IIIIIIOII§III ---- i'°--
0.00 200.00 400.00 600.00 000.00 ”the "We" “1"“ added
Time 8 33.44, then the upper
curve might represent
- the actual data (the
1- :: PSL default template Temp A vs Time 10%? WW8)-
;360 ...—PE . ' This means that the possible
p f theoretical approximate
"/—The starting point is 33.?0299. equation is:
A 34.0 . . . . Temp = L069‘TOIIIII}
+3344

 

0.00 200.00 400.00 600.00 000.00
Time s

Figure 4-20 Graph of LOG(A4)/LOG(9) vs. experimental graph

Actually, he could use the same method to construct different curves with
different bases (e.g., 8, 7, 11, 12) to find the best one to represent the "real-time"
experimental data. It seemed this curve with base 9 represented the data well enough, so
he stopped trying other bases.

When Subject 21 was asked about the theoretical foundation and the strategies
that he used to perform this approximation, he said, "The heating curve looks like a
logarithmic function when its base is greater than one. The PSL allows users to export
the data to a spreadsheet program. It is then possible to create a function in the
spreadsheet program that produces a curve which is close to the experimental data.“ He

felt confident about the equation that he had found; he opened the Data Table from the top

109

menu and showed the data to the researcher, “The experimental data and the
approximation data were very close. Therefore, he concluded that the approximation
data was accurate enough to represent the experimental data.

He also pointed out that if the base were less than 1, the shape of the curve would
be faced up, and could be used to represent the cooling curves. Figure 4-21 shows the
cooling curve that subject 21 obtained. To experiment with the cooling, he used a
different approach. (For further information about the law of cooling, see Thomas
Greenslade's article, “The Coffee and Cream Problem“, Wiser, Vol. 32,
March 1994) He:

1) selected the One-Temperature set-up, and changed the Duration to 5
minutes (the scale of temperature in the graph was Celsius, not
Fahrenheit).

2) pulled out the extended temperature probe from the hot water and

began collecting data.

110

 

T COOLING Temp A vs Time
e 48.0 ‘ ‘ ’
m 1'
P440} . «
A i
40.0 1, After pulling out the
1; Extended Temperature
3 Probe from the hot
“'0’ "t ‘ ' ' water, he used the
‘5 PSL to collect the data.
32.0l '5‘ 1" " '-
x
xx.
28.0 \~
\
x,
\x
24.0 ‘ ‘5' , _L ’

 

0.00 75.00 150.00 225.00 (seconds)
Time

Figure 4-21 Cooling

 

 

EL

 

111

3) chose LOG (base 10) from the Calculate menu, the cooling curve

changed to:
T C? LOG COOL FIT Temprtvs Time
3. x.
1.20 .\
l3 . \\
p, 0'80 \‘1. . ‘ After choosing LOG (base 10)
? 0 40. ; ‘3‘ _' -. from the Calculate menu,
' \k the curve changed. It looks
..........\ likeastraightline.Then
030...”... N'x' W 5ubject21decidedto use
_ 0 40 . . xx . the Fit-line command to find
' ' ' ‘1' its equation.
5|.
-O.80 . . .1.-
t.
-1.20 . . . L,
”'l
“1.60 3 '. -. L

 

 

0.00 75.00 150.00 225.00 (seconds)
Time

Figure 4-22 After applying LOG(base 10)

4) used the Fit-line command from the PSL to find the equation to
represent the above graphs, then converted the Fit-line equation to
the cooling equation.

Note: This approach was faster than the first approach.

The third approximation he completed involved a simple pendulum. He:

1) collected data from a simple pendulum by using the PSL.

112

2) customized the shape of the wave to make the starting point either
maximum or minimum by using the PSL, so as to more easily find a
formula to fit it. (by deleting some of the point at the beginning).

3) exported the PSL data to MS WORKS.

4) opened this file from MS WORKS, deleted the columns of velocity and
acceleration, and created a new column named c0328.

5) input a formula:
=0.01 002*cos(2*PI()*112*A3)+o.o1 802 (Note: P10 is

it).

File Edit Print select Format Options View
=0.01802*CO$[2*P1{)*1/2*A3J+0.01802

 

 

 

 

I coszs.wks
[ A B c D E
l2 s m l

s 0 .075000 0 .03604

4 0 . 100000 0 . 03552 0 .03510

e 0 . 125000 0 .00535 0 .0346?

6 o . 150000 0 .03403 0 .os4oa Siflfifflgmfi'f "we“

7 0 . 175000 0 .03443 0 .03330 = 0 01302*cos('2*p|()
g8 0.200000 0.03344 0.03200 *'1r2*03)+ 0 01802
'30 0.225000 0.03292 0.03172 (Note. '

. 0 .250000 0 .03171 0 .03070 ' .

in 0 .275000 0 .03102 0 .02972 0131302131“ “WWW"
| 12 0 .300000 0 .02931 0 .0205: ”‘38!” Simple Pendu‘um-

. . - - 13 ‘H.
, li2is the frequency ofthe

simple pendulum.

A3 represents the time.
Subject 21 obtainedthese
data from the data he

collected.)

Figure 4-23 A column with a formula

=0.01802*COS(2"P|()*1/2'A3)+0.01 802

113

6) went back to PSL and opened the curves.

m Pendulum Approximation Dist vs Time

 

 

 

‘ ‘\ (A). /A\
s \t ’2' x. I’ x
t 0-02 K ‘ ,1 ' 1t f ‘ ‘1 The uppper wave is the
K j ‘1‘ a" \R wave that Subject 21
0.00 xv! xv; \\ collected bu using
.....i“ .....,.......,. the PSL.
1.00 2.00 3.00 4.00 .
Ti me
The lower wave was
C m Pendulum Approximation C0325 vs Time created DU "3109
_ MS wonxs.
0 \ ‘~ /5\
3 x z x / t
\ I x x t ,
2 \ I t , i . t The theo retical
0.02 t I t r ~. . .
3 ‘1 r, t\ I t approx1mation seems to
t z t f ‘t, coincide with the
0.00

 

upper wave.

Figure 4-24 Pendulum Approximation

The two curves in Figure 4-24 show that the curve of COSZS vs. Time (an

approximation) and the curve of the Distance vs. Time (real-time data) match.

The fourth approximation was used to determine the spring constant K from the

PSL. From the curves of the Mass-Spring Oscillation, Subject 21 discovered how to use

the PSL to solve the spring constant K. His strategies in completing this approximation

are as follows:

Based on Hooke's Law, the restoring force of a spring is directly
proportional to the displacement: F = - K X. (here F is the restoring

force, K is the spring constant, X is the displacement). Applying Newton's

114

second law (i.e. F = ma, here F is the force, m is the mass, a is
acceleration ), the formulas are:

me = - KX

mIK = - Xla
If a ( acceleration ) and X ( displacement )are known, then 11th can be

calculated.

Subject 21 used PSL to collect the data of Mass-Spring Oscillation as follows:

 

 

 

D Determine K (constant) Dist(X) vs Time
1 1143'.) . I“) in! ‘ )At 1 IA‘
3 t r 1 ’1 ‘ I 81 1’
t 0.42 ‘t f 1 - 1 i - x v j The upper curve indicates
( t f 1,. j 1‘ f 1‘ f the relationship between
x 0.41 1:1 I. 1‘ ’1‘ 1* I ‘1‘ {I the displacement and time.
) V V. 'r' .V
1 OO 2 00 3.00 4 00
Time The lower curve indicates
relationship between the
accelerlation and time.
A Determine K (constant) Acc(A) vs Time
0 0.03 J. , 1" 11.4 ,0. Both the upper wave and
c {grit r'v . g lI In" the lover wave have the
-( '1 l '1 .i t. ‘9 tn same period. however.
AO.OO “m“, ”" "Df‘fiffi, theirdirection is opposite.
) a! t ..t t .N 1".“ n
“003! - I111! a “VI 4 '11N . “I:
1.00 2.00 3.00 4.00 .
T1 me

Figure 4-25 Determining K (constant)

After examining both the upper wave (Distance vs. Time) and the lower wave
(Acceleration vs. Time), Subject 21 said he could use the above method to find equations

to represent these two curves, and then found mIK by dividing these two equations. He

115

tried this way several times, each time he got a different value of mIK. He could not

find a satisfactory solution using this method.

He thought for a while and devised another approach, ”If we create a graph

displaying acceleration against distance, then we may find the mm by simply using the

Fit-line function to determine the Fit-line equation of acceleration against distance. The

slope of the Fit-line equation of acceleration against distance will equal le."

Following this new direction, the first important thing to do was to create a graph

of acceleration vs. distance. He explored the Reset Parameters on the top menubar

and produced the following graphs:

 

 

D Determine K (constant) Dist(X) vs Time
1 043k ' thi ' (At ‘ 1A1 ‘ JA‘
3 ix :1 i‘ ’t 1‘ ’r it )1
t 0.42 I. r t - r t - r v i
( 's I 1. i 1 f 1 1
t If t r t t t ’1
X 0.41) ‘1 2 . ‘1 I! t-r’ "t. r
) V - V. '.v' .V
1.00 2.00 3.00 4.00 .
Time
D Dist vs.Acc
, Dist=-b*Accl + c
1 0.4

 

 

 

-1.50 -0.75 0.00 0.75

1.50
Accl miss
KofFandX.vrks determine K (constant)

Subject 21 used the

Reset Parameters on the
top menubar to create a
graph of Distance vs.
Acceleration.

Then he used the

Fit-line function to find
the fit-line equation of
Distance vs. Acceleration.
The slope -h0f the fit-line
equation is equal to unit.

Figure 4-26 Finding the spring constant K by using the Fit-line equation

116

When the subject was asked whether he felt confident about discovering the value
of mIK, he replied, ”The Fit-line equation is based on the Least-Square-Criterion, it is
the best line to represent the data."

Discussion:

Subject 21, was a graduate student majoring in engineering who had a strong
computer background. He stated that he had a difficult time trying to find an equation
that represented the data that he obtained from these experiments while he was an
undergraduate students; he was interested in approximation. In approximately three
hours, he completed four theoretical approximations: 1) a heating curve (measuring the
body temperature), 2) a cooling curve (a cooling temperature probe), 3) a simple
pendulum wave and 4) a graph for determining a spring constant K. His approach in
doing approximation was logical and had a very clear direction. His performance
reflected his subject-matter knowledge and his computer experiences.

He used two methods to complete the above four approximations.

Method one: Combining the PSL and MS WORKS spreadsheet, he:

Step 1: created an appropriate experiment set-up and collected data by
using the PSL, then saved this data.

Step 2: exported the data collected from the PSL to a MS WORKS
spreadsheet.

Step 3: added a column in the MS WORKS spreadsheet with an appropriate
formula.

Step 4: returned to PSL, imported the spreadsheet (completed in Step 3)
to PSL and opened this new file to display the curves.

Step 5: compared the shape of the curve which represented the collected
data with the shape of the curve which represented the formula

added in Step 3. If their shapes were almost the same, he used the

117

calculation function to adjust them so that they became the same.
If their shapes were different, repeated Step 2 to Step 5 until both
shapes were the same.

Step 6. combined the formula input in Step 3 and the calculation in Step 5
to write down the equation. This was the equation that represented

the data collected from the "real-time“ experiment.

Method two: Using PSL only, he:

Step 1: created an appropriate experiment set-up and collected data by
using the PSL, then saved this data.

Step 2: analyzed the curve and found an appropriate calculation to change
it into a straight line (or almost a straight line).

Step 3: marked this straight line (or almost a straight line), then used
the Fit-line function to show its equation.

Step 4: combined the Fit-line equation that obtained in Step 3 and the
calculation that used in Step 2 to write down the equation. This
was the equation that represented the data collected from the real-
time experiment.

Subject 21's case suggested that the PSLs environment allowed more
knowledgeable users to experiment with multiple approaches to a solution. It provided a
variety of tools in order to make it possible to accommodate different leamers' prior
knowledge and experiences. These tools supplemented each other. The tools that Subject
21 used in order to determine the spring constant k were good examples. Subject 21
exported the "real-time“ experimental data to the MS WORKS spreadsheet and simply
calculated the spring constant k by dividing the distance with the acceleration. The
physical concept was very clear in this approach because it showed the direct

relationships among the spring constant k, distance and acceleration. However, he could

118

not find an appropriate solution using this approach. Finally, this lead him to explore
and discover a better way--use the Fit-line tool, to find an accurate solution. In solving
this problem, the capability of exporting data to a spreadsheet program provided Subject
21 a tool to calculate the spring constant K directly. However, 'the Fit-line tool provided
him a more accurate way to find a solution. These tools provided an opportunity for
Subject 21 to solve the same problem with various approaches.

Upon completion of these four approximations, Subject 21 said, "I could not

imagine that l accomplished them so fast (in three hours)."

Finding 3: Approximation requires both strong computer experiences and subject-
matter knowledge. In this study, two subjects participated in level three,
but only one was able to do the approximations. The approximations that
Subject 21 completed reflected his level of thinking. Subject 21's case
suggested that the PSL did not teach him how to do approximations, but that
the PSL environment assisted him in accomplishing the approximations
faster and more accurately than was possible in a traditional physics
laboratory. Subject 21's case also showed that the PSL helped him bridge
the gap between theory and practice. For example, in order to determine
the spring constant K, theoretically, he could find le by dividing
acceleration by displacement. However, he did not get a satisfactory
solution, since he obtained different values for mIK each time when he
divided acceleration by displacement. His experimentation led him to
discover that the Fit-line equation usage was more practical. If a teacher
were present to provide stimulation and assistance, perhaps more students .

could have performed these approximations.

119

l 0.°-"° 0‘01 .0.‘ :I'. l' .-. .-Ionoro : 11:: 1‘

f | ' ?

Data analysis involves numerous calculations. In traditional experiments, these
calculations were very time consuming. In program-based experiments, students need
to know programming in order to use computers to analyze data. The capability of using
the calculation commands which the PSL provides is a needed innovation. A positive
aspect of PSLs calculations, is the fact that the students do not have to spend hours
Ieaming computer programming. However, at level one, both subjects from high school
and middle school did not explore the calculations that the PSL provided. In order to
investigate how well subjects understood the calculation processes when the PSL
performed them, those subjects from high school and middle school who performed the
Mass-Spring experiment at level two were encouraged to try ADD, SUBTRACT,
MULTIPLY and DIVIDE.

Table 4-8 summarizes the subjects' responses to ADD A CONSTANT and
SUBTRACT AOONST ANT oomrnands.

120

Table 4-8 Summary of responses to ADD & SUBTRACT:

 

 

 

 

 

 

 

 

Was able to Was able to Was able to Was able to
explain changes explain changes explain changes ex pl 01 0 changes
Subject in PSL graphics in PSL graphics in PSL Table in PSL Table
(Year in when applging when applging when applging when applging
school) ADD command to SUBTRACT com- ADD command to SUBTRACT com-
graphs? mand to graphs? graphs? mand to graphs?
Subject 1 Yes Yes Yes Yes
(11)
Subject 3 8. Yes Yes Yes Yes
Subject 4 Yes Yes Yes Yes
(11)
3UP]: 3°“ 93‘ No Yes Yes Yes
301313320 No Yes Yes Yes
3qu cc“ 38‘ No Yes Yes Yes
“ 1:9,) No Yes Yes Yes
301315;; 1 1 Yes Yes Yes Yes
'Subiect72 Yes Yes Yes Yes
,Graduate student)

 

 

 

 

 

 

When they chose ADD A CONSTANT and entered a value of a constant (e.g., 2) from
the Calculation menu, the Mass-Spring wave moved up 2, but the wave shape remained
the same. Three subjects from high school and one subject from middle school found the
changes on the Y axis and were able to explain them; four subjects from middle school
could not identify the changes and therefore, could not explain them. After choosing
SUBTRACT A CONSTANT and entering a value (e.g., 2), every subject noticed that the
curves changed back to the original position. By repeating ADD A CONSTANT, then
SUBTRACT A CONSTANT and comparing how the figures changed in the Table (a type of
spreadsheets, where data were displayed), the subjects understood better how ADD A
CONSTANT and SUBTRACT A CONSTANT worked. It appeared they recognized changes on g .
the Table more quickly than on the graphs display. Perhaps, this was because the
numbers changed in the Table, but the shape of the graphs did not change when a
calculation command i.e. ADD A CONSTANT or SUBTRACT A CONSTANT, was applied.

121

Figure 4-27 and 4-28 illustrate the calculation process of Add A CONSTANT.

 

lNo. Time Distance ' I

 

 

 

 

 

 

 

 

 

P ”-520 (‘1 j“) 1 0.08 0.623 1
13 1 11 j. 1' 1 2 0.10 0.524 Before choosing
t 1 ii; iii 3 0.12 11524 ADDACONSTANT
i 1 '1 1 1 4 0.15 0.622 (8.0.2).thefirst
0.600 1 1 ‘ 1‘ 1' ' 1 5 043 0.520 digit on the Distance
1 1" 1 1 1| 6 0.20 0,515 column is zero.
1 § 1 1 1| 7 0.23 0.611
1 1 ‘ 1 1 ‘ l 8 0.25 0.606
0'53” i, ,r j j j 9 0.23 0.599
g j . 1 1 . j 10 0.30 0.593
1 1 1I l1 1 ‘1 11 0.33 0.586
0.560 1| 1 i: { It I. 12 0.35 9.578
1 1 ' ' 1 1
ii 11 ii Morel
11 .- 1.) ,- 191 .
0.540 " Before choosing ADD A
I 0.00 2.00 4.00 6.00 8.00 Time CON§TA"T,{F-9-2)»
the fi rst digit on the

 

Y axis is zero.

Figure 4-27 Before adding 2 to a graph

In Figure 4-27, all the first digits of numbers on the Y axis were zero and all the
first digits of numbers in the Data Table were zero before subjects applied calculation
commands. After they applied ADD A CONSTANT and entered 2 (i.e. added 2 to the
distance), the graphs and the Data Table changed to Figure 4-28 (see next page). Notice
that all the first digits in the Distance column of the Data Table and on the Y axis had been
changed from zero to 2 simultaneously. However, the shape of the graphs was unchanged.
Subjects noticed the changes on the data table more quickly than they noticed the changes

on the labels of the Y axis, perhaps because the shape of the graph remained unchanged.

122

Figure 4-28 follows this explanation.

 

 

 

 

 

 

    

 

 

 

 

After choosing ADD A
CONSTANT (e.g.2),the graph
keeps the same shape. \. No. Time Distance ,
@
P 2-5201 ,1", in) 1 0.00 2.623 1
1 1l 11 j I1 1 2 0.10 2.524 After choosing
1 1 i 1 1’1 3 0.12 2.624 ADDACONSTANT
2 600 1 1 1 1 1 4 0.15 2.622 (80-2); the fi I'St
. 1 : ~ .1. 'j ' 1 5 0.13 2.520 digit on the Distance
1 1 1 1 1 5 0.20 2.616 column changes
1 1 1 1 1| 7 0.23 2.611 from zero to 2.
1 I ‘ 1 1 ‘ t 8 0.25 2.606
2'58“ 1, j 1 j j 9 0.20 2.599
1' 1 . 1 1 I 10 0.30 2.593
1‘. '1 1 Ii 1, f1 11 0.33 2.586
2.560 5' g 1: If g 1' 12 0.35 %.5?8
1 1 ' l 1 1 1
1 t 1 1 1 1
ii ‘0‘ ii ,
2.540 " ‘ ' " " After choosing .100 n
I 0.00 2.00 4.00 6.00 8.00 Time EEeNflgfligft-fiflfie
Y axis changes from
zero to 2,

Figure 4-28 After adding 2 to the graph

Table 4-9 summarizes their responses to MULTIPLY and DIVIDE commands.

123

Table 4-9 Summary of responses to MULTIPLY & DIVIDE:

 

 

 

 

 

 

 

 

 

 

 

 

 

Was able to Was able to Was able to Was able to
ex plai 0 changes explain changes explain changes explain changes
Subject in PSL graphics in PSL graphics in PSL Table in PSL Table
(Year in when appiging when applying when appigi ng when applging
school) MULTIPLY com- DIYIDE command MULTI PLY com- DIYIDE command
mand to graphs? to graphs? mand to graphs? to graphs?
'Subject 1 No Yes Yes Yes
(11)
Subject 3 & No Yes Yes Yes
Subject 4 No Yes Yes Yes
(11)
Subject 1 9& No No Yes Yes
Sub jfcgzo No No v33 v33
8
Subject 1 3& N0 NO NO Yes
Sub j ectl 4 N0 No No Yes
(7)
SUbjl'ec: 1 1 N0 "0 Yes Yes
7
Subject 22 Yes Yes Yes Yes
{Graduate student)

 

The graphs resulting from applying the MULTIPLY BY CONSTANT command were
more difficult for subjects to interpret. Even subjects from high school took quite some
time to figure them out. When they chose the MULTIPLY BY CONSTANT command and
entered a value (e.g. 2), both the shape of Mass-Spring wave and the numbers on the Y
axis changed. The subjects found changes easily this time, but these changes did not make
sense to them since the changes were different from the changes in ADD A CONSTANT and
SUBTRACT A CONSTANT commands. After applying the reverse command DIVI DE BY
CONSTANT (e.g., 2), they saw the graphs change back. By comparing the numbers in the
Data Table, Subjects found the relationship and understood the calculation process
better.

It appeared that some subjects from the middle school and some subjects from
high school had difficulty in understanding the changes on the computer graphs after they

applied a calculation command to them. However, they explored some ways to understand

124

how the calculation worked and under what conditions they could use them correctly. For
example,

Subject 13 & Subject 14 tried the Calculate function after they collected data
from the mass-spring oscillation (level two experiment). First, they chose Add a
Constant command and entered 2, the wave moved up, but they did not recognize the
change. Then they chose Subtract a Constant command and entered 2. The wave moved
back to the original place. In order to test their result, they repeated the above
procedure. This time they recognized what the Add a Constant and Subtract a Constant
commands meant. They used the same procedure to figure out what Multiply by a
Constant and Divide by a Constant commands meant. Subject 13 said, “PSL can be used
to teach mathematics.“

Subject 3 81 Subject 4 explored the more advanced Calculate function after they
collected the data from the Mass-Spring Oscillation (level two experiment). First, they
chose the Differentiate from the curve of Distance-vs.-Time. The shape of the new
curve became the same as the curve of Velocity-vs.-Time. Second, they chose the
Integrate from the Velocity-vs.-Time curve. The curve changed to the shape of the
Distance-vs.-Time. Subject 4 concluded that the "differentiate“ of Distance vs. Time
was the velocity and the "integrate" of Velocity vs. Time was the distance. Subject 3
understood these mathematical processes by comparing the addition and subtraction,
“they are reverse operations.“

Subject 22 was a computer science and a mathematics major. He was interested
in the calculation option. He understood more about calculations than the other subjects.
Based on his experimentresults, he tried ADD A CONSTANT, SUBTRACT A CONSTANT,
MULTIPLY BY A CONSTANT, DIVIDE BY A CONSTANT, DIFFERENTIATE and INTEGRATE
commands. He understood the calculation process very well and he used the same
methods as Subject 13 81 Subject 14, and Subject 3 & Subject 4. Subject 22 knew that
some calculations, such as LOG(base 10), ANTILOG(10th power), SQUARE ROOT,

125

RECIPROCAL, POWER, SINE and COSINE, must meet unique mathematical conditions. If
the needed conditions were not satisfied, the calculation process would not proceed or the
calculation results would not be accurate. In order to apply these calculations to the
data, one needed to adjust the data so that they fit the mathematical conditions. For
example, LOG (base 10) command does not allow a zero point. In order to use LOG(base
10) in the PSL, the user must eliminate all zero points. In addition, some commands
have different‘formats in the various programs. For example, the SINE command uses
the form Sin(21t ft +0) and 11: is replaced by P10 in most spreadsheets and on graphs
calculators. The PSL, SINE function uses the form Sin(360ft+c). Since Subject 22
could not find this information from the PSL manual, he discovered his own method to
figure out how the calculation process worked and under what mathematical conditions he
could use each calculation. After he figured them out, he said, 'I feel confident in using
these calculations.“ Refer to the following illustration stating how he understood the
calculation process.
1) He exported a PSL file which gave the experimental data to MS

WORKS and deleted other columns except column A (Time), he

then created two new columns: column B with a formula, "=

360*1/2‘A4' and column C with a formula, "=

SIN(‘2*PI()*1/2*(A4))'.

Then he saved this file as "SIN2PIFT.WKS"

 

126

File Edit Print Select Format Options View
SIN(2*PI()*1/2*{AA))

A

8
0 . 00000

O.16d78|29-65977fl

0.32955
0 .49433
0.65911
0 .82388
0.98866
1 .15344
1 .3182!
1 .48299
1 .6477?
1 .81254

8

SINZPIFT .NKS

C

0 E

 

I .

 

59.319541
88.979312
118 .63908
143.29885
177.95862
207 .61838
237.2781?
266.93793
296.59771
326.2574?

l—T *

   

O - (190311137
0.8600263
0.9998413
0 .8776562
0.5254837
0.0356212

-O.A6858
-0.B41305
"0.998572
-0.894172
*0.555462

=SIN(2'PI()‘1/2‘(A4)

Created a second
column with the
formula:

= 360*1!2*A4

 

- Created a third

column with the

formula:

= SlN(2*Pl()*1!2*(A4))

Figure 4-29 Two columns with formulas =360‘1/2‘A4 and

2) He used PSL to open file, 'SIN2PIFT.wks", the following graphs were

displayed:

127

 

 

 

 

S PSL default template SIN360FT vs Time
I 1111111111111011111111111111.11 Thisgraphshows
N ”'7511111111111111111111111.11111111111111111 811136011 vs.Time-
3 11.111111111111111Illlllll'fllllllfllllll 11111111 11111111

[11111111111111mm||||.1IIIIt.I_1IIIIl, Illllltt,.lliltlli
6 ° °°1'""1"111111111111111111111111111111111 1111.111: 01....
° 111111111"1111111111111101.1111i11111 3'1360FT=3‘"‘36°"1
P117511111111111111111111111111'11111 :isthefgequencg.
T 0.00 20.00 40.00 ‘3 "“8'

Time
This graph is

360FT vs. Time

 
 

 

 

3 PSL default template 3501-1 03 Time
3 f"; lfthe user chooses SINE
F 8000i . ”a” from the Calculate menu,
T ,0.»- this graph will become
40001 #2.!" -' the same as the upper
...” graph.
0.0014577........ . . . . . .
0.00 20.00 40.00
Time
Figure 4-30

3) He made the lower graphs active and chose SINE (360 degree)

function. The lower graph became the same as the upper graph.

Through the above exploration, Subject 22 found that the conditions in using the
SINE command in PSL and in MS WORKS were different: In the PSL program, one must
use 360 degrees and in MS WORKS one must use 21:.

He used the same method to find the conditions of using the COSINE correctly.
Discussion:

According to Sherry Turkle's findings, children who were nine or older were in
the third stage and their performance were reflections of their minds. All the subjects
in this study were older than nine and would have been in the third age level category.
Their performances while using the computer program reflected their thinkings.

Subjects 13 81 14 (middle school students), and Subjects 3 8 4 (high school students)

128

understood the calculation processes in the PSL by using the reverse operation. Once the
calculation results on the computer screen matched their mental image, they understood
the calculation processes. Subject 3 was taking Introductory Analysis at that time, and
knew the concepts of differentiate and integrate, but had not used. them to solve a physics
problem like the Mass-Spring Oscillation. Subject 4 was taking physics at that time,
but had not Ieamed how to differentiate and integrate. Subjects 3 and 4's explorations
helped them find the relationship between Differentiate and Integrate. Subject 3 said,
”they are reverse operations."

One thing should be pointed out: the reverse operation was not available for some
calculations in the PSL program, such as POWER, SINE and COSINE. A person with a
very strong background in mathematics and computer science, like Subject 22, would
not feel confident in using the computation in PSL. They needed to fully understand under
what mathematical conditions they could use these calculations confidently. In order to
do so, the PSL program should provide some ways to help users understand easily how
the calculation process works. Because the PSL did not provide enough capability for
Subject 22 to do this kind of exploration, he used MS WORKS to determine under what
mathematical conditions he could used the calculations correctly.

Since the subjects from middle school had not Ieamed the functions of the graphs
in their mathematics classes, they were not accustomed to reading the changes that
appeared on the graphs. For example, when a Mass-Spring wave moved up 2 places after
they chose ADD A CONSTANT and entered 2, some of them were not able to find the
changes because the wave shape was still unchanged. Only the values on the axis changed.
It would be useful for the PSL program to provide some guided practices for users to
understand the calculation process. For those calculations which have reverse
operations, it appears helpful to guide students to use the reverse operation in order to
increase their understanding of the calculation processes. For those calculations which

do not have reverse operation, it seems important to allow them to input a formula to

129

test their calculation so that they understand under what mathematical conditions they
can use them correctly.

A subject from the seventh grade commented, "The PSL can be used to teach
mathematics.“ This raised an interesting point: Could a teacher take advantage of the PSL
to teach mathematics? One result of this study indicated that subjects from middle
school were not accustomed to reading the changes that occurred from the graphs after
they performed a calculation. How then could the PSL be used to teach mathematics? The
questions here are, “Should students learn the graphs of functions in the mathematics
class first in order to read the PSL graphs? Could a teacher take advantage of the PSLs
capabilities, such as 1) immediate feedback, 2) high interaction, 3) reverse operation
and 4) data presented in both graphs and Tables, to teach the graphs of functions?"

Further discussion will be included in Chapter five.

Finding 4: There were three high school students, five middle school students and one
graduate student who tried the calculation commands in the PSL. They
tended to understand how the calculations worked and under what conditions
they could use them correctly. It took quite some time for subjects from
middle school to understand what changes occurred on the computer graphs
after they chose simple calculations. They subsequently understood the
calculation processes by using the reverse operations and by comparing the
data in the Table and the data presented on the graphs. For some calculation
commands, reverse operations were not provided; at least one subject
discovered his own method to determine under which conditions they could

be used correctly.

I30

1.: :1 1 o = o 11:. an: 0.0 0110.: 02-1 1‘0 -9 :01 -10: -.1-. 1‘

The data presented in the previous section indicated that the tabular data helped
the subjects from the middle school understand the relationship between the changes and
the calculation commands after they applied ADD A CONSTANT and SUBTRACT A CONSTANT
to a Mass-Spring wave. It seemed that they identified the changes from the tabular data
better than they did from the graphical data. However, the following examples illustrate
that the computer graphs helped subjects understand the subject-matter in different
perspectives.

When viewing computer graphs like Temperature vs. Time, Distance vs. Time and
pH vs. Time, subjects were not only able to tell how much the temperature, distance or
pH value changed; they were also able to tell which temperature, distance or pH value
changed faster and how the graphs changed. The “real-time“ computer generated graphs
helped the subjects get a broader view of how the variables changed in the experiments.
This suggests that the PSL computer graphs helped subjects understand the subject-
matter knowledge better.

There are six examples from level one and two in this section. Each example
illustrates different aspects of the PSL graphs and how these graphs helped subjects
understand the subject-matter knowledge of physics, chemistry or mathematics. The
following overview may help understand the subsequent detail.

Example 1: A subject in eleventh grade, when performing a pH experiment, said,

'It take time to stabilize.“ (level two experiment)

This example shows how the PSL graphs helped Subject 1 Ieam that
stabilization of the pH probe took much longer than he expected, even
though he was a lab assistant in a chemistry class at that time.

Example 2: A subject in ninth grade, when performing a temperature

experiment, said, 'There is a little pot.“ (level one experiment)

131

The PSL graphs helped Subject 2 Ieam not only how much the
temperature changed (the end result), but also how it changed (the
changing process).

Example 3: Two eighth grade subjects, when exploring a two-probe temperature
experiment, stated, "What made this different." (level one
experiment)

Subjects 9 & 10 found an interesting phenomena with the help of the
PSL graphs. Their casual finding enhanced their understanding about
temperature.

Example 4: A seventh grade subject, when analyzing the temperature
experimental data, said, "It is different from what I feel.“ (level one
experiment)

With the help of the PSL graphs, Subject 11 concluded that the room
temperature was lower than the cold water in that room. This
enabled him to realize that subjective feeling was different from
objective measurement.

Example 5: Two eleventh grade subjects, when exploring the calculation
commands, stated, "The derivative of distance respect to time is the
same as velocity” (level two experiment) -

By exploring the calculation functions and the computer graphs in
the PSL graphs, Subjects 3 & 4 understood some mathematical
concepts with a physics application. The PSL graphs helped them to
establish a relationship between abstract mathematics concepts and

concrete physics phenomena.

132

Example 6: Two seventh grade subjects, when analyzing the experimental
results, said, “It depends“ (level one experiment)
This example showed that the PSL graphs assisted Subjects 13 81 14
to understand what phenomena occurred and under what conditions
they occurred.

The following examples provide more detail.

Example 1: Subject one, when performing a pH experiment, said, "It takes time to
stabilize“ (level two experiment)

Subject 1 was taking a chemistry class at that time and was interested in using
the pH probe to test the pH value of the drinking water in the fountain.

In the first experiment, he set-up a data collection for 60 seconds, the graph he

produced is shown in Figure 4-31.

 

 

9” 6.2
5.3
1 Time
60 Seconds

Figure 4-31 The pH value was increasing

133

From the graph, he knew the pH value was still increasing, so he repeated the

experiment and obtained the second graph.

 

 

H
p 7.2
6.31
1 Time
60 Seconds

Figure 4-32 The pH value was still increasing

Because the second graph still showed the pH value increasing, he repeated the

experiment one more time.

pH

 

7.5

"3.2

 

 

' Ti me
60 Seconds

Figure 4-33 The pH value increased and then became stable at 7.5

134

The third pH graph showed that the pH value increased and then became stable at
7.5. i
From the pH curves he stated that:
The computer figured it out, left it in for a long time. It takes time to
stabilize, it stabilized at about 7.5. (Note: the pH ranges from 0 to 14.
Solutions with pH less than 7 are acidic, while solutions with pH greater
than 7 are basic.)

Subject 1 did not initially realize stabilization would take so long. Because the
pH was still increasing after the first 60 seconds experiment; he repeated the
experiment two more times. After the experiment, he said that, “It (pH) took more
time to stabilize." The “real-time" computer graphs helped him understand how long it
took to stabilize the pH value, and which pH was the stabilized value.

Example 2: Subject 2, when performing a temperature experiment, said, 'There
is a little pot" (level one experiment)

Question: When you put the temperature probe into the cold water, will the

temperature go down straight?

Subject 2 said, 'It goes down, but there is a little pot.“

Subject 2 put the temperature probe
into the cold water at this time.

 

p l? .

H
r \ a o
o 21 .o: \

l \ From the cooling curve Subject 2

x / ’ 1

3 18.0% ' \\ ' realized that the temperature

1 "x. “goes down, but there is a little pot.“

15.0} f . 44 ________
0.00 20.00 40.00

Time
Figure 4-34 There was a little pot
Subject 2 was a ninth grade student. He had not Ieamed Newton's law of cooling,

but from the "real-time" computer graphs, he realized the cooling curve was not a

135

straight line, "there is a little pot". The “real-time” computer graphs helped him
understand how the temperature changed (the changing process), not just how much it

changed (the final results).

Example 3: Subject 9 81 Subject 10, when exploring a two-probe temperature
experiment, stated, said, "What made this different” (level one experiment)

After Subject 9 and Subject 10 completed the first level experiments, they
continued to experiment with the PSL. Subject 9 placed both temperature probes in the
same container to see if probe A and probe B showed the same temperatures. The results
showed that the short one (standard probe) displayed a higher temperature than the long
one (extend probe). Subject 9 told Subject 10, ”These two probes were different."
Subject 10 looked at the computer graphs. The computer graphs showed the difference.
Then she examined the two temperature probes and the container. She explained, “This
was because these two probes were placed in a different spot, and the different spots had
different temperatures in the same container. The short probe floated in the middle of
the container, so it indicated a higher temperature, and the long one touched the bottom
(closer to the ground) so it indicated a lower temperature.“

Both Subject 9 and Subject 10 seemed to believe the computer graphs because
they could view the two “real-time“ computer graphs on the computer screen
simultaneously. Subject 9 and Subject 1O explained the temperature curves in different
ways. The interesting thing here was not whose explanation was correct. Rather, it
showed that the computer graphs, which simultaneously displayed two different
temperature curves, helped the students realize that the two probes indicated different
temperature and stimulated the students to pose questions.

Later, the researcher tested both probes. The probes worked fine at that time.

Subject 10's explanation was logical.

136

Example 4: Subject 11 81 Subject 12, when analyzing the temperature experimental
data, stated, ”It is different from what I feel" (level one experiment)

When the computer program finished collecting data, the researcher asked
Subject 11 and Subject 12 which graphs represented the temperature in the room and
which one represented the temperature in the cold water and hot water.

Subject 11 stated, “The room temperature is right here, the cold water is higher
(than the room temperature). This is a cold room.“

Subject 11's findings from the computer screen surprised this author, because
he felt cold when he used the cold water from the faucet before the experiment began.
After he examined the temperature curves, he believed that the computer graphs were
objective and that his feeling about the cold water must have been subjective. Subject

11's observation was correct.

Example 5: Subject 3 81 Subject 4 , when exploring the calculation commands, stated,
“The derivative of distance with respect to time is the same as velocity“ (level two
experiment)

After they collected the data from the Mass-Spring Oscillation, Subjects 3 814
explored the mathematical function of PSL. First, Subject 3 chose Differentiate from
the curve of Distance-vs.-Time. The shape of the new curve became the same as the
curve of Velocity vs. Time. Later, Subject 3 chose Integrate from the Velocity vs. Time
curve. The curve changed to the shape of the Distance vs. Time. Subject 4 concluded
that: the derivative of Distance vs. Time was the velocity, the integration of Velocity vs.
Time was the distance. Subject 3 understood these mathematics processes by recalling
what she Ieamed from an introductory analysis class.

Subject 3 had taken an introductory analysis class and was familiar with
differentiate and integrate. She wanted to see how these calculations worked. Subject 4

was taking a physics class at that time. The real-time computer graphs showed them the

137

connection between distance and velocity and helped them recall the knowledge they had

Ieamed in their analysis and physics classes.

Example 6: Subject 13 & Subject 14 , when analyzing the experimental results, stated,
“It depends" (level one experiment)

Subject 14 said, “Does the temperature increase or decrease when you
blow on the probe?“

Subject 13 said, "From here (they started blowing) it increased, from
there (they stopped blowing) it decreased" as she pointed to
the graphs on the computer screen.

The graphs showed how the temperature changed. Subject 13 was able to tell
when the temperature increased and decreased. It helped her understand the conditions
that caused the temperature to increase and under what condition the temperature

decreased.

Discussion

Subject 1's chemistry teacher stated that Subject 1 was his lab assistant. From
Subject 1's experiment with the pH probe, it was concluded that be underestimated the
time for stabilization twice. Had Subject 1 used a traditional method (e.g. a pH meter) to
test the pH value, it would have been possible for him to read the pH value after 60
seconds. If a traditional method had been applied, he would not have been able to find the
correct pH value. However, the “real-time“ computer graphs told him that the pH value
was not stabilized after his first and second trial. He continued to run the experiment
until he discovered that the pH value stabilized at 7.5.

When a cooling object is observed with a thermometer, it is not uncommon for
middle school and high school students to focus on how much the temperature changes and

ignore the important concept of how the temperature changes. This is because a regular

138

thermometer is not sensitive enough and the students' observations are not fast enough to
read the changes every 0.02 second (i.e. the sampling rate of the temperature probe).
Therefore, students focus on the end results (i.e. how much it changed) and ignore the
changing process itself (i.e. how it changes). However, the PSL. is not only sensitive
enough to show small changes, it is also able to display the changing process on the
computer screen. This changing process stays on the computer screen as long as students
need to read it (the experimental data stay on the computer screen until subjects delete
them). This capability provided subjects an opportunity to observe something they were
not able to observe in an experiment with a thermometer and allowed subjects to take as
much time as they needed in order to examine and analyze the experimental results.
Some subjects took advantage of this capability to Ieam something new. For example,
Subject 2 viewed the experimental results from another perspective--how (i.e. the
way it changes), Subject 11 found the room temperature was lower than the cold water
from the faucet, and Subjects 13 81 14 understood the conditions that caused the
temperature changed.

The capability of showing two graphs on the computer screen simultaneously
helped subjects compare their experimental results or analyze the results. For
example, it helped Subject 9 and Subject 10 discover a phenomena that the water
temperature in the same container was not necessarily the same. It also helped Subject
3 and Subject 4 understand the relationship between the curve of Distance vs. Time and
the curve of Velocity vs. Time.

What was the difference for the subjects from middle school between reading the
graphs from a first-hand experimental data and reading the graphs after applying a
calculation command (e.g. ADD A CONSTANT or SUBTRACT A CONSTANT)? When the
subjects from middle school viewed graphs from the experiments, the changing
processes from the graphs helped them make connections between the data and the

physical phenomena. For example, when they saw the pendulum move far away from the

139

motion probe and the indication of the distance on the computer graphs move upward,
they understood that a "moved upward“ in the computer graphs corresponded to "far
away“ in the pendulum experiment. In the temperature experiment, when they touched
the temperature probe, the computer graphs moved up. So they understood that "moved
up" in the computer graphs corresponded to “temperature increase" in the temperature
experiment. In these situations, the difference is that the "real-time“ experiment data
provided a direct changing process, and the calculation process was not observed by the
subjects. On the other hand, the final products of some calculation commands (e.g., ADD
A CONSTANT and SUBTRACT A CONSTANT) did not change the shape of the graphs, only the
number on the side of the Y-axis changed. It was difficult for a subject who had not
Ieamed the graphs of trigonometric functions to understand the meaning for these
changes. In this situation, the tabular data provided by the PSL helped them find the
changes, since all the numbers in the corresponding column changed and the subjects

from middle school were accustomed to reading these kinds of changes.

Finding 5: Computer graphs helped subjects comprehend the subject-matter in
different ways: i.e. viewing the experiment results from various
perspectives, such as: how and how fast etc.; thinking about why;
establishing relationship; and talking about the experiment more
accurately. This led the subjects to understand the experiment results
more readily. In order to read some computer graphs correctly, subject-
matter knowledge was needed. It seemed that subjects from middle school
read changes from the tabular data easier than from the graphs when they

applied a calculation command.

II
n
y.

140

110.: -_ 1: 0.:

Some subjects had never used computers, while some subjects had computer

experiences before they participated in this research. All the subjects in this study

were volunteers. They enjoyed using the PSL and had a positive attitude change after

they used the PSL. The following responses and dialogues illustrate the subjects' attitude

toward the PSL.

Table 4-10 Summary of the subjects' attitude toward the use of PSL

 

 

 

 

 

 

 

 

Subject Their observed attitude What d0 900 think about the 00 9°" WMJ
(Year in while doing the PSL PSL? to learn more
school} experiments. aboutthe PSL.
Subject 1 Followed the instruction (After completing leve I)
(11) step- bu-step. ”Actuall g it is a verg good
program, but right now is
not that challengi ng."
(Aftercompleting level 2) Yes
" Ed ucational , right now I
just Know very basic ...... It
is a good program, it would
be a good program for
college student."
Subject 2 Read the instruction "It is easy to use."
(9) carefull g and followed the v33
procedure step-bu-step.
Subject 3 Concerntrated on howthe ”It is a lot of faster ......
(11) graphics changed on the You don't have to write it v33
computer screen. down."
Subject 4 Gave suggestion to her "You don't have to check the
(1 1) partner and made two experiment everg two Yes
hgpotheses and tested them. seconds."

 

 

 

14

Table 4-10, continued

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Teacher)

 

PSL."

 

 

Subject 5 81 Theg read the instruction Subject 6:"Verg nice
Subject 6 carefullg and took turns program,
(8) pressing the kegboa rd kegs. I like it." Yes
Sometimes they discussed
ideas with each other.
Subject? & Sf“? often asked S.*8 for
Subject 8 help before moving next step. Subject 8: "It is an
(8) 8.488 watched to the interesting
experiments verg carefully, program." V83
and she corrected S.*?'s
observations sometimes.
Subject 9 81 Concentrated, stricklg - . . .
Subject 10 followedthe instruction, SUbJeCt to'plrmsgglfi.
(8) did eXtra work after “139 subject 9 u't i3 833'; to Yes
completed the experiments ' understand it ..
at the first level. '
Subject 1 1 Actively explored everg "Very nice program,"
(7) thing; he was interested.
Carefullg compared Yes
his calculation results with
the PSL computer graphics
to find the errors in his
calculation process.
Subject 12 Was 15 minute late. Watched how Subject 1 1 did the experiment for a
(7) while, then left.
Subject13& Both read the instruction Subject l4:“l like it."
Subjectl 4 very carefulig,theg signaled Subject 1 3:”lt is pretty easgl Yes
(7) each other to press the to use ."
computer kegs.
Subject15& Quiet, stricklg followed "It is easy to use."
Subject 16 the instruction.
(7) Yes
Subjectl 781 Explored something they "it is easy to use."
Subject 18 were interestedin. Yes
(7) Sometime then; got lost, in
this situation,theg did itover.
Subject19& Verg happu, enjoyed using Subject 19:"lt is cool."
Subject20 PSL-T1189 390'“! OUt and Subject 20:"Yes.“
(7) talked a lot. Theg said Subject 19:"lt is mi racle." V83
"Cool i", "It is mi racle." and
"It is fun." quite often.
S.*21&22 Concentrated. "Good enough for research." No
(Graduate students)
Subject 23 Curious. “I felt confident in using the Yes

 

 

142

Discussion

In order to find some connections from the data in Table 4-10, the subjects were
separated into two groups (The two groups were formed only for discussion purposes in
this section). Group one includes subjects who had better computer/science experience.
Group two includes subjects who had less computer or no / science experience.

Group one included: Subject 1, Subject 3, Subject 4, Subject 21 and Subject 22.

Subject 1 was an eleventh grade student. He knew several computer programs
and had experience in spreadsheets. After he completed the first level, he said “the PSL
is not that challenging.“ When he finished the second level, he realized the PSI. could do
much more than what he had anticipated. Then he changed his thinking and said “... it
would be a good program for college students."

Subject 3 did not have much computer experience, but had a better background in
chemistry and mathematics than other high school students. In chemistry class, Subject
3 read the temperature from a thermometer and recorded its changes on a piece of paper.
After using PSL to do experiments, Subject 3 concluded that, 'It (the temperature
experiment) is a lot faster. You don't have to write it down.“ (Note: the highest sampling
rate of the PSL was 34 times per second. It was impossible for a student to read the
temperature change and recorded them on a piece of paper that quickly.)

Subject 4 was the only student who had taken physics among the grade school
students and also knew how to use data bases and spreadsheets. She missed the first two
experiments at level one and joined Subject 3 in the third experiment at level one. Upon
completion of the third experiment (two temperature probes) at level one, she said,
."You don't have to check the experiment every two seconds." As mentioned earlier, she
measured the period of a simple pendulum by counting 1, 2, 3 ...... 16 and then divided
the time by 16. By using the PSL, she discovered some differences that she did not find
when experimenting with the problem in her regular physics class. As a matter of fact,

she formulated two hypotheses and used the PSL to test them. The capabilities of the PSL

143

encouraged her to investigate the simple pendulum problem in more depth than she had
done in her regular physics class.

Subject 21 had a very strong background in mechanical engineering and
computer science. After completing four approximations, he was impressed with the
PSLs potentials. He thought both sample rate (34.1 samples/second for the motion
probe) and the accuracy (six significant digits) of the PSL were adequate for research
usage.

Subject 22 recalled that his friend (a Ph. D candidate in Crop and Soil Science)
recorded the temperature day and night. He said the PSL could help his friend save time
and energy, since the PSL was able to collect temperature data and save the data in the
computer.

The more the subjects Ieamed about the PSL, the more new ideas they generated
using the PSLs capabilities. Some of them were immersed in exploring something. For
example, both Subject 21 and Subject 22 spent three consecutive hours in Ieaming and
applying the PSL. They were impressed with PSLs capabilities after they used it.

Group two included: Subjects 2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,

18, 19, 20 and 23.

These subjects had little computer experience and/or science background. Table
4-10 shows that most of them were very quiet and followed strictly the prescribed
procedures to perform the experiments in level one. They did not try alternatives.
After they completed level one, all of them stated that: 'The PSL is easy to use.", 'The
PSL is an interesting program." or "I like it.“ It appeared that their satisfaction with
their success in experiments enabled them to feel confident in using the PSL. Some
subjects tried some alternatives or something new. For example, 1) After Subjects 9
and 10 completed the two temperature probe experiment, they placed two temperature
probes into the We water container. An interesting thing happened: two temperature

probes in the same water container indicated two different temperatures. This differed

144

from their previous experiment which they placed one temperature probe in cold water
and another in hot water. Therefore, they actively tried to find a reasonable explanation
in order to understand this phenomena. (For details, see research question five) 2)
After Subject 11 completed level two experiment, he was interested in the Fit-line
equation. Actually, he did not know what Fit-line meant. The interesting thing was that
the PSL encouraged him to explore something beyond his knowledge and he was immersed
in doing this exploration after he knew how to use the PSL (for details, see research
question two). 3) When Subject 13 understood the calculation process, she stated:" PSL
can be used to teach mathematics" (for details, see research question four). These
examples indicated that once these participants became comfortable users of the PSL,
they sought more creative ways to use it.

Most of the subjects in this group seldom talked. However, two pairs of subjects

talked constantly. The following dialog is only a sample of their conversations.

Pair one: Subject 7 81 Subject 8 (level one experiment)
Subject 8 said, "Highlight graph, let me do it."
Subject 7 said, 'Do you want to do it ?"
Subject 8 said, "Read it for me.“
Subject 8 81 Subject 7 said, ." Zoom into the marked region."
(When they saw the enlarged area)
Subject 7 said, "It's a miracle.“

Subject 7 never used a computer for academic purpose except playing computer
game before she used the PSL. Subject 7's teacher said she was not a smart student.
However, she was not afraid to try. Subject 8 knew wordprocessing, but she never used
the PSL. While Subject 8 was still reading the instruction, Subject 7 followed the

instruction and started the PSL. After watching how easily Subject 7 used the PSL,

145

Subject 8 felt confident in using it too. She wanted to switch the position and asked
Subject 7: “Let me do it.“ Subject 7 seemed to feel proud of herself and replied: "Do you
want to do it?" Subject 8 said: "Read it for me.” While Subject 8 was pressing keys on
the keyboard, Subject 7 was actively keeping her eyes on what was happening, on the
computer screen. Their conversation suggested that Subject 8 was eager to operate the
PSL once she realized it was easy to use. Their conversation also suggested that Subject
7 felt confident after she successfully started the PSL and became an active participant.
For those experimental results obtained by using the PSL, they exclaimed, “It's a

miracle.“

Pair two: Subject 19 and Subject 20 (level one experiment)

Subject 19 said, ”Then touch the probe, wave it in the air, or blow on it."
( Both tried the probe these ways. )

Subject 20 said, (While watching how the temperature changed )" This is
fun.“

Subject 19 said,“ Type 2" (Zoom in ).

Subject 20 said, “OK.“ (She typed Z and the graphs she had marked
became enlarged)

Subject 20 said, “Oh, you have to type Z 1" (She was surprised and
laughed for a while)

Subject 20 said, 'Oh, look at, look at... " ( She pointed to the enlarged
graphs. )

Subject 19 said,“ Cool !"

Subject 19 said, 'Yes, it is cool."

Subject 20 said, “This is fun."

146

Subject 19 and Subject 20 had known each other since fifth grade. Their
conversation was very informal and the above conversation was just one example of
their experimentation. Actually, the researcher heard “fun“, "cool“ and ”miracle” from
them all the time. The more capabilities of the PSL they Ieamed', the more they said the

PSL was 'fun", "cool' and a “miracle".

Finding 6: After completing level one, all the subjects stated that: the PSL was a very
good program and was easy to use. All of them had a positive attitude toward
the use of the PSL. For those subjects who had more computer or science
experience, the more they used the PSL, the more they Ieamed that the PSL
could be used. The graduate students thought it was good enough for some
types of research studies. For those subjects who had less computer or

science experience, the more they tried the PSL, the more they liked it and

felt more confident in using it.

 

Table 4-11 shows subjects' computer background and Table 4-12 shows

subjects' subject-matter background.

147

Table 4-11 Subjects' computer background

 

 

 

Subject '1'
1234567891011 1213141516171819 20212223
Had used a computer? 3 '
at home X X X X X X '1'. X X
atschool XXXXXXXXXXXEXXXXXXXXXXX
Software experience? E
computergame XXXXXXXXXXXEXXXXXXXX
wordprocessing XXXX XXXX 3X X XXX XX
data base X X E X X
spreadsheets X X 3 X X
statistical anal 1,1313 3 X X
software 1:
math, science and E X X
engineering software 2
programming language X L5 X X
Hours spentfper week 5
lessthan2 XXX :3 XX X X
2-5 X X X X X X X X X X
over 5 X X X X X
Had taken computer class? X X X X X

 

 

 

Table 4-11 indicates that Subjects 1, 4, 21 and 22 had more computer

experience than other subjects.

148

Table 4-12 Subjects' subject-matter background

 

 

Subject 1"
1234567891011121314151617181920212223
Takengeneralsciencein XXXXXXXXX X X X X X X 'X X X X X X X X
middle school or
high school?
Taken chemistryin high X X X X X X
school?
Taken algebrallin high X X X X X X
school?
Taken introductory X X X
analysis in high
school?
Taken physics in high X X X
school?
Taken physics in college? X X
Majors
mechanical engi nee ri ng x
mathematics x
computer science x

 

 

 

 

Table 4-12 indicates that Subjects 1, 3, 4, 21 and 22 had more content subject-
matter knowledge than other subjects.

The results of the survey on Table +10 and Table 4-11 suggested that Subjects
1, 3, 4, 21 and 22 had more computer skills and content subject-matter knowledge than
other subjects.

In order to discuss whether subjects who have more computer skills and content
subject-matter knowledge interacted with the PSL differently from those who do not
have these skills and knowledge, the author separated the subjects into two groups:

Group one: This group had better computer and science content experience. This
group included Subjects 1, 3, 4, 21 and 22.

Group two: This group had less computer and science content experience. This
group included Subjects 2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20

and 23.

149

Most of the data in Table 4-13 and Table 4-14 are based on the data presented in

the previous sections. These two tables summarize subjects' abilities in using the PSL.

Table 4-13 Summary of subjects' interaction in group one

 

 

 

 

 

 

 

 

 

 

 

 

Tried Was able Was able Was able
alternatives to make to formulate to formulate
while connection hypothesis procedures
fOWWiW the With prior for further which the
prescribed knowi edge investigation? manual did
procedures in order to not provided?
to perform understand
Levels completed: experiments experimental
one two three inlevel one? results?
11 l X X Yes Yes Yes Yes
45 3 X X Yes Yes Yes No
.3 4 X X Yes Yes Yes Yes
‘3 21 X X X Yes Yes Yes Yes
‘0 22 X X X Yes Yes Yes Yes
Table 4-14 Summary of subjects' interaction in group two:
Tried Was able Was able Was able
alternatives to make to formulate to formulate
while _ connection hypothesis procedures
following the with prior for further which the
33:25:32 #:3339430 investigation? manual did
to perform understand "°t ”fwd“?
Levels completed: experiments experimental
one two three inlevel one? results?
2 X X Yes Yes No No
5 X No No No No
6 X No No No No
7 X No No No No
8 X No No No No
9 X Yes No No No
10 X Yes No No No
* 1 l X X Yes Needed clue Yes No
33; 12 (Was late and left early)
33‘ 13 X X Yes Needed clue N0 N0
in 14 X X Yes Needed clue No No
15 X No No No No
16 X No No No No
17 X No No No No
18 X No No No No
19 X X Yes Needed clue No No
20 X X Yes Neededcl ue No No
23 X X Yes Yes No No

 

 

 

 

 

 

 

 

150

Table 4-15 Generalization of Table 4-13 and Table 4-14 by comparing

Group one and Group two:

 

 

 

 

 

Tried Was able Was able Was able
alternatives to make to formulate to formulate
while connection hypothesis procedures
followingthe With prior forfurther whichthe
prescribed knowledge investigation? manual did
procedures in order to not provided?
to perform understand
Levels completed: experiments experimental
one two three inlevel one? results?
Group 5 5 2 5 5 5 4
one
(Five § § § 100% 100% 100% 80%
, c1 0 v
subjects) '- -
GFOUD 17 7 0 9 2 1 0
two
(Eighteen § 2,? § 50% 11% as 0%
subjects) °' ’0

 

 

 

 

 

 

 

- In group one, five of five subjects (100%) completed level one. Five of five
subjects (100%) completed level two. Two of five (40 %) subjects completed level
three.

In group two, seventeen of eighteen (94%) completed level one. Seven of
eighteen subjects (39%) completed level two experiments. Zero of eighteen (0 %)
subjects completed level three experiments.

0 In group one, five of five subjects (100%) tried alternative methods while
following the prescribed procedures to perform experiments in level one.

In group two, nine of eighteen subjects (50%) tried alternative methods while
following the prescribed procedures to perform experiments in level one.

o In group one, five of five subjects (100%) were able to make connection with

prior knowledge in order to understand experimental results.

151

In group two, two of eighteen subjects (11%) were able to make connection
with prior knowledge in order to understand experimental results. Five of eighteen
subjects (28%) needed clues in order to make connection with prior knowledge for
understanding experimental results.

0 In group one, five of five subjects (100%) were able to formulate hypothesis
for further investigation.

In group two, one of eighteen subjects (6%) were able to formulate hypothesis
for further investigation.

0 In group one, four of five subjects (80%) were able to formulate procedures
which the manual did not provide.

In group two, zero of eighteen subjects (0%) were able to formulate procedures
which were not in the PSLs manual.

In general, group one had a high percentage in participating in a high level of
experiments, such as trying alternatives, making connection with prior knowledge and
formulating new procedures.

The followings provide more details about the differences of group one (had better
computer while science content experience) and group two (had less computer and

science experience). Their differences are compared within five categories:

1) Ability to participate in higher levels of experiments

Table 4-13 and 4-14 show that group one had higher percentage of subjects who
participated in higher level of experiments. These data indicate that the more computer
and science knowledge that subjects had, the more likely they were to participate at a

higher level of usage of the PSL.

152

2) Ability to try alternatives while following the prescribed procedures to perform

experiments in level one

a) Subjects in group one:

All subjects in group one tried some alternatives in the level one experiment.
For example, they tried different experiment set-ups or tried a different way to alter
the temperature on the temperature probe. Trying alternatives meant that subjects did
something which the prescribed procedures did not define. For example,

Subject 1: In the simple temperature experiment, the prescribed procedures
asked subjects to choose One Temperature vs. Time experiment set-up to collect
temperature data. Upon completion of the experiment, Subject 1 selected Two
Temperature vs. Time set-up to measure the temperature.

Subject 3: To practice the reset parameters commands, the prescribed
procedures asked subjects to set up two of reset parameters, i.e. Duration... and Ranges
of axes..., in level one activity 2---Creating an Experiment. Subject 3 tried another
parameters command, i.e. Axis variables....

Subject 4: In level one activity-3---Selecting and Running a Two-Probe '
Experiment, Subject 4 suggested Subject 3 choose Type of Plot command and select
Points to see how the computer graphs changed.

Subject 21: Upon completion of level one activity-3, Subject 21 used the Two-
probe experiment to test how the Calibrate. command worked. In his experiment, he
calibrated probe A with the number that was indicated on probe A and he did not calibrate
probe B (i.e. used 500 as the default value). Then he placed both probes on the desk to
measure the room temperature in order to see the difference.

Subject 2: In order to change the experiment set-ups, he tried all the Reset
parameters commands, i.e. Axis variable..., Duration..., Labels..., Numeric format...,

Ranges of axes... and Type of plot....

153

b) Subjects in group two:

Nine subjects in group two tried alternatives, eight other subjects in group two
strictly followed the prescribed procedures. For example,

Subject 2: After following the procedures to place the temperature probe in the
cold water first and then place it in the hot water, Subject 2 tried an alternative way of
placing the temperature probe in the hot water first and then in the cold water.

Subjects 9 and 10: After they completed the level one activity in which they
placed two temperature probes in two different beakers, they then placed two
temperature probes into the same water container and found these indicated two
different degrees of temperature. (See research question five for details)

Subject 11: In practicing the View command in the level one activity-3, a small
window showed that Temp A was in Port 1, Channel 1 and Temp B was in Port 1, Channel
2. Subject 11 tried to change the port number, but was unable to do so. Although his
trial was unsuccessful, he did try an alternative.

Subjects 13 and 14 used two temperature probes to test their hand temperatures
after they- completed level one activity -3. They selected the Two Temperatures vs. Time
experiment set-up and each person held one temperature probe to compare their hand
temperatures.

Subjects 19 and 20 did some alternative experimenting with the Two
Temperature vs. Time experiment. After they tried with one temperature probe in the
cold water and the other one in the hot water, they pulled out the one in the cold water
and placed it in the hot water, so that the two temperature probes were in the same hot
water container at the same time.

Subject 23 put the temperature probe into the cold water and then pulled it out. .
He did this several times and created very interesting graphs. (See research question

nine for details)

154

Subjects 5, 6, 15, 16, 17 and 18 did not try any alternatives when they
performed the level one experiments. They did not speak of their thoughts aloud. They
strictly followed the prescribed procedures while they were performing the
temperature experiments. When they made a mistake or got lost, they simply started
the experiment over. Subjects 15 and 16 completed level one with only one repetition.
Subjects 5, 6, 17 and 18 completed level one with two repetitions.

Subjects 7 and 8 did not try any alternatives when they performed the level one
experiments. However, they talked and thought aloud. (See research question eight for

details)

3) Ability to make connections with prior knowledge in order to understand
experimental results and the ability to formulate hypotheses

a) Subjects in group one:

All subjects in group one were able to apply their prior knowledge to
understanding the experimental results. In addition, they were able to formulate some
hypotheses based on their observations. For example,

Subject 1 measured the pH value of the drinking water in the fountain, his prior
knowledge of chemistry helped him understand that the pH value took time to stabilize.
However, the pH curve of the first 60 seconds did not convince him that the pH value had
been stabilized. He stated: "It probably takes longer time to stabilize." In order to test,
if the pH value took longer to stabilize, he repeated the experiment twice until he
obtained a stabilized pH value. In this case, Subject 1's prior knowledge, that it would
take time for the pH value to stabilize, played an important role in encouraging him to
investigate whether the actual stabilization time of the pH value took longer than he had
estimated. After he repeated the experiment twice, he concluded that ”The computer
figured it out, left it in for a long time. It takes time to stabilize, it is stabilized about

7.5.“ (See research question five for more details) In answering the question about the

 

 

 

 

 

 

155

pendulum clock, he was able to make connections among the variables of change of
temperature, change of length and change of period.

Subject 3: In the level one experiment, all subjects from the middle school and
three subjects from the high school who had not taken physics were not able to explain
the difference between what they observed from the temperature probe and what they
felt on their skin. Compared to the other subjects who had no physics background,
Subject 3's response indicated that she was able to make a connection with her prior
knowledge'of science and formulated a hypothesis through this statement, “Maybe
because your body temperature is higher than your breath, something like this.“ (See
Table 4-3 in Research Question One) In answering the question about the pendulum
clock, Subject 3 was able to make connection with the change of temperature, change of
length and change of the period.

Subject 4's pendulum experiments demonstrated that her prior knowledge of
simple pendulums played an important role in helping her to formulate two hypotheses.
In her physics class, she counted 1, 2, 3 ...... 16 and divided the time by 16 in order to
find the period of a simple pendulum. The simple pendulum experiment in her physics
class was based on an assumption that each swing took the same time. The simple
pendulum experiment on the PSL showed that the time interval of each swing was not
exactly the same. The concepts she Ieamed in her physics class and the experimental
results she obtained from the PSL helped her formulate two hypotheses and test them.
(See research question one for more details) In answering the question about the
pendulum clock, Subject 4 was able to make connections among the change of
temperature, change of length and change of period.

Subjects 21 and 22 faced a challenging phenomena concerning the simple
temperature experiment. As mentioned earlier, they had a good background in physics.
In an informal conversation, both of them admitted that when they took physics classes

in college, they had already known the answers before they took the examination.

156

However, the PSL experiment created a challenging problem for them at that time. They
were not sure what caused the difference. Their background in physics helped them
formulate some logical assumptions in order to explain the phenomena. (See research
question one for more details)

b) Subjects in group two:

On the other hand, only two subjects in group two were able to recall their prior
knowledge of science in order to explain the difference between what they observed on
the temperature probe and what they felt on their skin. For example,

Subject 2 said the cause of the difference was, “The temperature in the room is
cold. When I blow on it (the temperature probe), it gets higher...“

Subject 23 stated that the cause of the difference was evaporation.

Subjects 5,6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20 had no
theories about causations of the difference.

In answering the question about the pendulum clock, subjects in this group (i.e.
11, 13, 14, 19 and 20) were able to make connections with the change of temperature,
change of length and change of period when they were provided the clue, 'Will the
pendulum become longer or shorter when the temperature is higher?“

One Subject (i.e. Subject 11) was able to formulate some hypotheses about the

Fit-line equation of the marked points. (See research question two)

4) Ability in formulating new procedures

a) Subjects in group one: ,

Subjects 1, 4, 21 and 22 were able to formulate some procedures which the PSL
manual did not provide in order to accomplish their tasks. For example,

Subject 1: In the level two experiment, he created a new procedure to establish
an experiment set-up to show the relationship between temperature and pH value. The

following is the procedures he created:

157

First he created a coordinate under the software's Temperature option.

Temperature

 

Ti me

 

Figure 4-35 A set-up of Temperature vs. Time

Secondly, he changed the X-Axis variable from Time to pH.

Temperature

 

 

pH
Figure 4-36 A set-up of Temperature vs. pH

Finally, he accepted this experiment set-up and started collecting data. Because
other equipment needed to alter the temperature was not available at that time, both
temperature and pH did not change considerably. This experiment showed that it was
possible to collect two different kinds of data at the same time by using the PSL.

Subject 1's designs for the pH vs. temperature experiment set-up reflected his ‘
computer and mathematics background. The PSL manual did not state these procedures in

this experiment's set-up at this time.

158

Note: This experiment set-up was successful. The researcher of this study was
surprised by this new design. The PSL manual said: The PSL was able to collect up to 5
kinds of data at the same time. Unfortunately, the manual did not show how to do it. The
researcher could not figure out how to do this before he saw Subject 1's findings.
Subject 1's performance helped him discover how to collect five kinds of data at the same
time.

Subject 3 did not create any new procedures.

Subject 4 tested her hypothesis about the time difference of each swing and
discovered a new procedure to determine the time interval accurately.

When Subject 3 opened the Table from the top menu, a window showed the data of

Time, Distance and Velocity. Subject 4 discovered a new way to measure the period from

the Table.

 
      

[11 3.1.3 01:13 "."el 13121 i 0

0.554

 

3.66 0.542

-l

:l.

. . :t$

1.54 0.542 : :1

1.55 0544 (peak 1) : :1

1.55 0.542 5 5 ,

a z t

. . : : 1
5.54 0.542 : :
5.55 0544 (peak 2) : :

 

 

1.55 3.65

Figure 4-37 Subject 4's idea in finding the pendulum period

159

In this case, Subject 4 knew how to use computer spreadsheets while Subject 3
did not. When she saw Subject 3 open the Table from the top menubar, she discovered
how to obtain the time interval between two peaks. Subject 3 saw the same Table,
however, she did not realize that the data in the Table provided a. more accurate way to
determine the period because she did not know the concept of spreadsheets at that time.
In order to find this new method to determine the time interval of each swing, a person
needs to make a connection between the maximum displacement of a pendulum and the
peak of a wave. In other words, Subject 4's discoveries reflected her computer and
physics background. (See Research Question one for details)

Subject 21 was able to combine other programs like MS WORKS spreadsheets in
order to complete some complex approximation. The new procedures he created involved
a great deal of computer skills and knowledge of physics. (See research question three
for more details)

Subject 22 was able to combine another program like MS WORKS spreadsheets to
complete some exploration of the calculation commands. The new procedures he created
.involved a great deal of computer skills and mathematical knowledge. (See research
question four for more details)

b) Subjects in group two:

Subjects 2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and 23
did not create new procedures. They used only the PSL manual's procedures. They either
strictly followed the prescribed procedures or looked for the instruction on the PSL
manual to perform their experiments.

In this group, one subject (Subject 2) chose the pH probe to design an
experiment set-up to collect pH value and temperature data simultaneously. His design
could be used to compare with Subject 1's design. Subject 2 followed the instruction in

the PSL manual to design his experiment set-up as follows:

160

First he created a coordinate like this:

pH

 

Ti me

 

Figure 4-38 A set-up of pH vs. Time

Second, be split the computer screen in order to collect two different sets of data

from one experiment:

Time

 

 

 

Time

 

Figure 4-39 Creating a set-up to collect two kinds of data

Third, he highlighted the upper coordinate and designed the experiment set up as

follows:

161

Temperature

 

 

 

 

Ti me

Figure 4-40 Subject 2's set-up of pH vs. Temperature

Discussion

The above data show that subjects who had more computer skills and subject-
matter knowledge were more likely to participate at a higher level of PSL usage. They
were more capable of using their prior knowledge in order to understand the
experimental results and formulate their hypotheses. If the need arose, they were able
to create some new procedures to accomplish their tasks. Subjects who had less
computer skills and subject-matter knowledge were less likely to participate at a higher
level of PSL usage. They seemed not to have enough prior knowledge to understand the
experimental results and formulate hypotheses. In order to accomplish their tasks, they
relied on either the prescribed procedures or the instructions in the PSL manual.

In this study, two subjects (i.e. Subject 1 and Subject 2) performed the pH
experiments. It was interesting to compare their subject-matter background with their
experimental set-ups. Subject 1 was an eleventh grade student and had Ieamed the
concept of Function in his mathematics class. Subject 2 was a ninth grade student who
had not Ieamed Function. In Subject 1's mind, everything he measured (including time)

was a variable. Temperature was a variable; pH was a variable; Time was also a

162

variable, so he could and did construct an experiment set-up of Temperature vs. Time,
pH vs. Time, or Temperature vs. pH. In Subject 2's mind, everything he measured was
vs. Time, Temperature should be vs. Time, and pH also should be vs. Time. Time was a
special measurement.

Figure 4-41 compares Subject 1 and Subject 2's two experiment set-up for
collecting two kinds of data (Temperature and pH value) at the same time. Their
experiment set-up reflected their different mathematics background. Subject 1

understood the concept of function and Subject 2 did not understand this concept.

 

 

 

 

T
e
m
P
T Time
e
"l p
P H
H
9 Time
Subject 1's experiment set-up Subject 2's experiment set-up
shows the relationship between shows the relationship between
temperature and the pH. temperature and the pH.

Figure 4—41 A comparison of Subject 1 and Subject 2's set-ups

Subject 1's design shows two kinds of data in the same coordinate because they are
two variables of a function. Subject 2's design shows two kindsof data in two separate
coordinates because he only knew that both temperature and pH changed as time
progressed.

Some evidence indicated that subjects‘ interests also reflected their background.

For example:

163

1) When Subjects 3 and 4 tried the differentiate and integrate commands on the
simple harmonic motion wave, Subject 3 related the change to a mathematics concept and
Subject 4 related the change to a physics concept. (See research question four for
details.)

2) Both Subject 21 and Subject 22 had experience in using statistical analysis
software, engineering packages/mathematics software, and programming languages.
They knew that some computer software programs were able to exchange data with other
programs. When the need arose and they realized that they could not accomplished their
tasks using the PSL, they explored the possibilities of combining other computer
software, such as MS WORKS and LOTUS 123. However, their interests were different.
Subject 21's approximations (for details see section “What approximation skills do
Ieamers gain from the PSL?") reflected his background in engineering. He tried to
explore some practical usage of the PSL. Subject 22's approach in determining the
mathematical conditions of the calculation command in PSL, (for details see session "Do
Ieamers understand the calculation process when the PSL does all of the calculation?)

reflected his background in mathematics.

Finding 7: Subjects who had better computer skills and more subject-matter
knowledge in science were more likely to participate in the higher level
experiments. They were more likely to recall their prior knowledge in
order to understand the experiment results and formulated some
hypotheses. Also, they were more likely to formulate new procedures to
accomplish their tasks when the need arose. Some evidence showed that
subjects' interests reflected their backgrounds (i.e. Subject 1's interest
in doing the experiment reflected his chemistry background, Subject 4's

interest reflected her physics background, Subject 21's interest reflected

164

his mechanical engineering background and Subject 22's interest reflected

his mathematics background).

': s._ I or 'e 'le: I1" .0001119 arc. e_..e- 010...: :11].
In this study, some subjects worked individually and some worked in pairs in
level one and level two. Table 4-16 shows their work style and the levels they

completed.

Table 4-16 Subjects' work style and levels of completion

 

Subject Year in school Worked individually Worked in pairs Levels completed

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Subject 1 11 X levels 1 81 2
Subject 2 9 X levels 1 81 2
Subject 3 81 1 1 S. 1113 completed Activity 1812 in level one, then worked
Subject 4 with S. *4in Activity 3 in level one and level two.
Subject 5 81
Subject 6 8 X level 1
Subject 781
Subject 8 8 X level 1
Subject 981
Subject 10 8 X level I
Subiect I 181 S. *1 I completed level one and level two.
Subject 12 7 S. *1 2 was 15 minutes late and left early.
Subject1381
SUbjeCt14 7 ' X levels 1 8'1 2
Subject1581
Subject16 7 X level I
Subjectl 781
Subject18 7 X level 1
Subjectl 981
Subject 21 Graduate stu. X levels 1, 2 81 3
Subject 22 Graduate stu. X levels 1, 2 81 3
Subject 23 Teacher X levels I 81 2

 

 

 

 

165

This table shows that almost all the subjects from middle school and two subjects
from high school worked in pairs. The researcher did not try to force collaborative. If a
subject came individually, he/she worked individually. If subjects came with someone, ,

they worked together. The following is a description of subjects. who worked in pairs.

Subjects 381 4:

SubjeCt 3's chemistry teacher said she was a very good student; Subject 4's
physics teacher said she was a very good student also. In this study, Subject 4 missed
the first two experiments because of personal circumstance (she went to a blood drive).
She joined Subject 3's experiment starting with activity three (Selecting and Running a
Two-Probe Experiment) in level one. Since Subject 3 missed the first two
experiments, she observed how her partner, Subject 3, performed the Selecting and
Running a Two-Probe Experiment. When Subject 4 saw Subject 3 type in a name 'T81R"
in order to save the data that was collected, the computer showed “Invalid name“, Subject
4 suggested to Subject 3, ”You can't go with '81' sign.“ Then Subject 3 changed the name
from "T81R" to 'TandR". After that experiment they moved to the simple harmonic
motion experiments, Subject 4 became more active. While Subject 3 was measuring the
time interval of each pendulum swing, she formulated two hypotheses. In testing the
second hypothesis, Subject 3 explored the Table menu on the top menubar, she
discovered a new way to determine the time interval. Subjects 3 and 4 worked together
and completed the Selecting and Running a Two-Probe Experiment in level one and the
simple pendulum experiments in level two. (See research question one for more
details) When they applied the Differentiate and Integrate commands to the Mass-Spring
wave, Subject 3 understood the changes by relating to the concepts she Ieamed from her .
Introductory Analysis class, Subject 4 understood the changes by relating to the concepts
she Ieamed from her physics class. Their prior knowledge (i.e. Subject 3' knowledge

about the concepts of calculus and Subject 4's knowledge concepts of physics)

166

supplemented each other's experimental application and helped them to make a
connection between the abstract mathematics concepts and the concrete physics

applications. (See research question four for details)

Subjects 581 6:

Subjects 581 6 had experience in computer games. They read the instruction on
their own but they took turns using the keyboard. In Creating an Experiment, Subject 6
omitted steps and became lost twice. They started the experiment over. They did not
share their thinking aloud. However, when they had a problem in understanding the
instruction, they discussed it. They completed the level one experiments. They stated

they would participate in level two, but never did.

Subjects 7 818:

Subject 7 only had experience in computer games. Her science teacher said she
was not an good student in her science class. However, she was not afraid to try. She
- started the PSL and collected the temperature data. Subject 8 had experience in word
processing and her science teacher said she was a good student in her science class. She
watched Subject 7 use the PSL for a while and said: “Let me do it.“ "Read it for me.“
Then they switched positions. While Subject 8 was using the keyboard, Subject 7 was
actively keeping her eyes on what was happening on the computer screen. In answering
the question, 'Does the temperature increase or decrease when you blow on the probe?“
Subject 7 looked at the graphs on the screen and said, "It decreased.” Subject 8 pointed
to the graphs on the screen and said, 'No, it can go up, increases." From then on, Subject
‘7 always asked Subject 8 for confirmation. For examples, when she was not sure the
next step, she asked Subject 8, 'Now what I ...... " "What do you want? Probe A, B or C.”
'Is that 482 number?" 'By the plastic wire?“ "Probe A? Which one is probe A?” It

appeared that Subject 8 became Subject 7's opinion leader in these experiments.

167

Subjects 9810:

Subjects 9 and 10 had experience in word processing. They seldom talked while
they read the instruction and pressed the keys on the computer keyboard. However,
when Subject 10 tried to get rid of a small warning window by pressing the ESC key,
Subject 9 examined the screen and discovered the problem. She pointed to the figure on
the screen and said, “Oh, it went higher, you have to get it back.“ Then Subject 10
realized that she had entered the number wrong. They completed level one successfully.
After they completed level one experiment, Subject 9 put two temperature probes into
the same water container. She found an interesting phenomena, the computer graphs
showed that these two temperature probes indicated two different temperatures. Subject
9's finding initiated a conversation between them because they explained this phenomena
in different ways. (See Research question five for details.) They stated they would

participate in level two, but they did not do so.

Subject 11 8112:

Subject 12 did not complete level one. Actually, Subject 11 completed all the
experiment by himself. Subject 11 had experience in word processing. He completed
level one without any mistakes and participated in level two. He made some mistakes in

level two. (See Research question two and five for details.)

Subject 138114:

Subjects 13 and 14 had experience in word processing. They seldom talked about
the experiments. They read the instruction on their own and signaled each other to press
-the computer keys in turn. In the simple pendulum experiment (level two), while
Subject 14 moved the arrow to find the corresponding time of each trough, Subject 13

recorded the corresponding time and calculated the time interval of each swing. They

168

completed level one accurately and participated in level two. (See Research question two,

four and five for details.)

Subject 158116:

Subjects 15 and 16 had experience in computer games. They did not discuss
anything about the experiments. They read the instruction on their own and pressed the
computer keys in turn. When they got lost once, they simply started the experiment

over. They stated they would participate in level two, but never did.

Subjects 178118:

Subjects 17 and 18 had experience in computer games. They did not speak or
discuss their ideas aloud. They were interested in the graphs. After they chose the Zoom
command and the Fit-line commands, they looked at the computer graphs for a while.
When they returned to the manual's instruction, they got lost. They completed level one

with two repetitions. They stated they would participate in level two, but never did.

Subjects 19 81 20:
Subjects 19 and 20 had known each other since fifth grade. They talked aloud.
The following is part of their dialog:
When they found something new and exciting, they shared it with each other.
Subject 20 said, " It is going to straight apart.“
Subject 19 said, “Let the experiment run for about 15 seconds to
establish a graph of room temperature ...... "
Subject 20 said, 'Wait a minute 1"
Subject 19 said, “Then touch the probe, wave it in the air, or blow on it.“

(Both tried the probe these ways)

169

Subject 20 said, "This is fun.“ while they watched how the temperature

changed.
When one had a mechanical problem in using the PSL and the other discovered the
solution, they helped each other.

Subject 19 said, “Press ESC twice to remove the windows."

Subject 20 said, (Subject 19 was holding down the ESC key, while
Subject 20 was typing the description, but Subject 19 could
not remove the windows because Subject 20 had not finished
typing yet.)

“You don't have to hold the ESC key down.“ (Subject 20
laughed at Subject 19.)

Subject 19 said, "Please let me know.“

Subject 20 said, “Because ...... “(While Subject 20 was laughing, she
pressed the Enter key to save the file, the windows were
ready to removed) '

Subject 19 said, “OK“ (She realized the windows could be removed) .

Subject 20 said, 'Now you strike (the ESC key) twice."

Subject 19 said, “(Pressed)ESC twice to remove the window.“

Subject 20 said, “Ah-ha, you got it, finally.‘

The following is another example shows how they helped each other to solve
another mechanical problem.

Subject 19 said, “What are you doing?”

Subject 20 said, "Enlarging it, in a minute."

Subject 19 said, “Move the pointer to the end of the area you want to

examine, then type 2 to enlarge the marked area.”

170

(Subject 20 did not listen to Subject 19 carefully. When
she finished marking, she kept pressing the Enter Key to
enlarge the area she marked).

Subject 19 said, “Don't press Enter to try (to enlarge)"

Subject 20 said, “I'm going ahead." (kept pressing Enter Key, but she
could not enlarge the graphs )

Subject 19 said, "Type 2 “(Zoom in ).

Subject 20 said,’ “OK (She typed Z and the graphs she marked were

enlarged)

Oh, you have to type Z ! (Felt surprised and kept laughing for
a while)
Oh, look at, look at... “(She pointed to the enlarged graphs)

Subject 19 said, " Cool 1"

In order to locate the exact point where they took the probe out of the cold water,
both of them watched carefully how the arrow moved on the computer screen and spoke
out.

Subject 19 said, 'Use the Right Arrow key to move the pointer to the place
on the graph where you took the probe out of the cold water.
Notice that the graph is highlighted as you move the pointer.“
( Subject 20 was moving the Arrow key to highlight those
points )

Subject 19 said, “Keep going.“

Subject 20 said, "I know, I am thinking about these points."

Subject 19 said, ”That's all, that's all."

Subject 20 said, 'No.‘

171

Subject 19 said, "I'm sure the temperature (when you took the probe out
of the cold water) on that place. (Subject 20 kept moving
the arrow key), up here ...... "

Subject 20 said, "Ah, you got your mind."

“Back one, go back one."

11112911551911

For pairs 3 814, 7 818, 9 81 10, 19 81 20, the observation in this study indicated
that there were many benefits:

1) Shared experiences to solve the mechanical problems in using the PSL are
listed:

a) Subjects found different methods to solve the file name. For
example, Subject 4 told Subject 3 to change the file name from 'T81R" to
'TandR" and got out of the problem.

b) Subjects discussed solutions to solve the problem of the
warning given in the windows. For example, Subjects 9 8110 worked
together and found that they entered the higher figure 100 in the Mini and
the lower figure 0 in the Max.

c) Subjects discovered how to remove the computers window. For
example, When Subject 19 could not remove the computer's windows on
the screen, Subject 20 told Subject 19: 'Now you strike (the ESC key)
twice.‘ In order to make sure she was doing it right, Subject 19 asked:
'(Pressed) ESC twice to remove the window?‘ Subject 20 confirmed her:
"Ah-ha, you got it, finally."

2) Questions that were raised about the data or given more attention were:
a) Subjects questioned the possibilities of various temperature

readings. For example, Subject 9 and Subject 10 questioned why two

 

172

temperature probes in the same water container indicated two different
temperatures.

b) Subjects raised attention for their partner to observe the
experiment reSUIts. For example, when Subject 20 saw the temperature
graphs on the computer's screen change, she called Subject 19's
attention," It is going to straight apart." (Note: the graph of the

' temperature was being drawn across the screen indicated that the
computer was measuring the temperature of the room.)

When Subject 20 found the marked region was enlarged, she called
Subject 19's attention again, "Oh, look at, look at... " Subject 19:" Cool I"

3) Subjects who discussed the data together:

a) Subjects discussed different data concerning temperature. For
example, when Subject 7 and Subject 8 completed the simple temperature
experiment, Subject 8 asked Subject 7, "Does the temperature increase
or decrease when you blow on the probe?" Subject 7 said, "It decreased."
Subject 8 disagreed, "No, it can go up, increases ."

b) Subjects discussed temperature events by using the indicator
on the computer. For example, when Subject 19 and Subject 20 tried to
exactly locate the point where they took the probe out of the cold water,
Subject 19 said, "Keep going." Subject 20 said, "I know, I am thinking
about these points." Subject 19: "I'm sure the temperature (when you
took the probe out of the cold water) was on that place. (Subject 20 kept
moving the arrow key ), up here ...... " Finally Subject 20 said, "Ah, you
got your mind. Back one, go back one."

4) Subjects' prior knowledge supplemented each other:
Subjects' prior knowledge of mathematics and physics

supplemented each other and developed a higher level of understanding of

173

the PSL experimental results. For example, Subject 3's mathematics
background and Subject 4's physics background helped them understand
that the "differentiate" of Distance vs. Time was the velocity and the
"integrate" of Velocity vs. Time was the distance:

Pairs 5 81 6, 13 81 14, 15 81 16, 17 8118 did not talk to each other about the
experiments. When some of them got lost, they did not ask questions and try to find the
problems. In order to move on, they simply started the experiments over. They read the
instruction on their own and pressed the keys on the computer keyboard in turn. Some
even signaled each other to press the computer keys. Their performances looked as
though they worked individually. The researcher did not find evidence which showed that
they cooperated with each other. It seemed that working in pairs did not provide
advantages for them. Later, the researcher talked to their science teachers. Their
science teachers said these students seldom talked and rarely asked questions in their
science classes either.

In this study, pairs 3 81 4, 9 81 10, 19 81 20 shared experiences to find
mechanical problems and solve them. On the contrary, pairs 5 81 6, 15 81 16, 17 81 18
solved mechanical problems by simply restarting the experiments. From the
observation, the researcher found that the mechanical problems that pairs 5 81 6, 15 81
16, 17 81 18 had were due to one of the partner's omitting steps or forgetting where they
were. Since they did not talk aloud, they probably did not know who omitted steps. The
simplest solution to continue the experiment was to start it over.

The case of Subjects 3 81 4 showed that working in pairs helped the subject who
was late. Subject 4 not only caught up the time she missed in Ieaming the PSL, but also
was able to give Subject 3 some suggestions to solve a mechanical problem. Her
performance in level two experiments demonstrated that she was able to use the PSL

very well. On the contrary, the case of Subjects 11 81 12 did not show that working in

pairs helped Subject 12 catch up on the information she missed because she was late.

 

174

Subject 12 watched Subject 11 worked for a short time, then left without saying

anything.
One question is raised in this study, ”What kind of situations seemed to make

collaboration work better?

In this study, pairs 3 814, 7 818, 9 81 10, 19 81 20 seemed to work better then
pairs 5 81 6, 118112, 13 81 14, 15 81 16, 17 8118. These two groups had the following
differences:

0 Pairs 3 814, 7 81 8, 9 81 10, 19 81 20 at least had computer experience in word

processing (except Subject 7). In pairs 5 81 6, 118112, 13 81 14, 15 81 16, 17 8118,

only Subjects 11, 13 and 14 had computer experiences in word processing. The others
only had experiences in computer games. (See Table 4-11 for further information) It
seems that the more computer experiences the subjects had, the better they cooperated.
- Pairs 3 814, 9 81 10, 19 81 20 stated that they had worked together. Subjects 7
81 8 said that this study was the first time they worked together, however, both of them
thought aloud and talked a lot. Pairs 5 81 6, 118112, 13 81 14, 15 81 16, 17 8118 stated
that the first time they worked together was in this study. They seldom talked or did not
talk at all. It seems that pairs who had worked together and thought aloud cooperated

better.
The following table shows their collaboration and their grade levels.

175

Table 4-17 Collaboration vs. grade levels

 

 

 

 

 

 

 

 

 

 

Subjects worked in pairs Year in school Collaboration
Subjects 3 81 4 1 1 Better
Subjects 5 81 6 8
Subjects 7 81 8 8 Better
Subjects 9 81 10 8 Better
Subjects ll 81 12 7
Subjects I381 14 7
Subjects 1581 16 7
Subjects 1781 18 7
Subjects 19 81 20 7 Better

 

 

 

 

 

At grade eleven, one of one pairs (100%) collaborated better.

At grade eight, two of three pairs (67%) collaborated better.

At grade seven, one of five pairs (20%) collaborated better.

It seemed that subjects who were at higher grade levels collaborated better.

Finding 8: In this study, some evidence showed that the PSL provided an environment

for 4 pairs of subjects (45%) to share their ideas to solve mechanical
problems, raise question about the data, initiate discussion about the data
and supplement their prior knowledge to understand the experimental
results. For 5 other pairs of subjects (55%), there seemed to be no
advantages. It seems that partners who ,had more experiences, thought
aloud, talked and cooperated better. It also seems that the higher subjects'

education level, the more possibility they cooperated better.

 

176

n: :2 1 0111: '0: 11° 0 ‘ 1: 011- .1: ‘21:: 0 -. :1 1: 7

The researcher tried very hard to invite more teachers to participate in this
study, but only one teacher participated. Computer readiness here means a teacher was
able to transfer his/her prior computer experience to the PSL environment and was able

to Ieam more as the need arose.

Subject 23 (level one and two experiment)

Subject 23 was a social science teacher in an elementary school. He had
experience in using a word processing program on a Macintosh computer, but had never
used IBM computers. By following the instructions, he successfully completed the three
activities in level one. When he calibrated the temperature probe, he forgot to press the
Enter key. In order to eliminate those small pop-out windows, he pressed the Enter key
first, but the Enter key did not work in this situation. Then he read the instruction and
tried the Escape key to eliminate the small pop-up window. After several times, he
discovered that the Enter key and Escape key were very important when using IBM
computers and their functions.

Subject 23 was very interested in the "real-time" computer graphs. When he

did experiments with the temperature probe, he made a temperature graph as follows.

 

 

177

 

 

 

test water temp Temp A vs Time
1 17.25 11 ' -' -'
e {Huh—4‘} a
. _ +1
m17.oo _ ,4: [Jul Subject 25 put the
p 16 751 l , I!" ‘1 1 1 temperature probe
A ' .1 If ', into the cold water
16 50 1 1’ ,’ l and then pulled it
' t 1’ ;’ tur" out. He did this
1 1 “1 several times.
16.25 1 I 1 1 .
1 1 1
| r
1 1 1
16.00 '- ~ -1 1 -
1 1 1
‘1 '1 l
15.75 111‘ - '1 I 11
V1 ‘— 3|
1 .i "1. 11
15.50 \N - WI .
l l '
15.25 ‘

0.

 

00 20.00 40.00 60.00
Time

Figure 4-42

Subject 23 understood all the graphs in the temperature experiments, but he

could not figure out why the following upper graph was flat when he was doing the simple

pendulum experiment.

 

 

178

 

 

m . .
i0 400 Pendulum 0131 vs. T1 me
f 3-00 After Subject 23
collected the data
2-00 ofthe simple
pendulum, he did
1-00 not understand
1.00 2.00 3.00 4.00 why the upper
Time graph was flat.
mfs
Pendulum Yel vs. Ti me
11 2.00
e
I
0.00

-2.00

 

 

 

1.00 2.00 3.00 4.00
Time

Figure 4-43

He read the PSL manual again and used the scale key to rescale these graphs. Then

he repeated the experiment, he realized the numbers on the axis changed when he

rescaled. From this procedure, he understood what "scale" meant and why the above

upper graph was flat.

179

Dist vs. Time

 

 

 

 

 

 

m Pendulum
D k
. A f‘x
1 ‘1 I x x x
3 1‘ I) \‘1 r, \\
t 0.420 1‘ r! 1‘ 1 1’ . 1‘
1 .1 t 1 1"? After Subject 23
‘1 ,1" ‘1, f “ pressed the scale
o 400 '~
1 9 ' V ". V 2 " key to rescale the
1.000 2.000 3.000 4.000 graph.The graph
Time — was enlarged and
the numbers on the
. . Y axis were changed.
”1,13 Pendulum Yel vs. T1 me
110.050 - /"\ 1 1 /'--., 1
e I \ x '1
I \ 1' 11
to 000 ....... A ...... 1...),3,
' r t .- "l.
‘1 .f S. a" t. X
x ,- \ x 1, .1
-0.050 \J'g . \v/g { \J’
1.000 2.000 3.000 4.000
Time

Figure 4-44 Simple Pendulum (after scale)

As a matter of fact, the PSL helped him make progress in reading graphs. He told
the researcher that the numbers did not make sense to elementary school students, but
elementary students would be able to understand computer graphs. A

After the experiments, he wanted to try an IBM word processing program. He
explored MS WORKS for a while and found that the ideas of MS WORKS and PSL were
very similar. He realized that ALT and TAB keys play an important role in MS WORKS.

He seemed proud of what he did and he said he could use the IBM computer comfortably.

He said the PSL helped him Ieam how to use an IBM computer.

Discussion:
Subject 23 had computer experience on Macintosh computers, but did not have

experience on IBM compatible computers. Sometimes he used the experience he had on
the Macintosh platform to solve problems he faced in PSL, but it did not always work.

Fortunately, the PSL allowed him to repeat the procedure again and again. The repetition

180

helped him discover some differences between Macintosh computers and IBM computers;
it helped him transfer his experience from Macintosh to the IBM.

Repetition seems to be a good way for the people to discover something. The
computer-based programs provided the kind of environment that helped users to Ieam
something by themselves. In addition, the immediate feedback helped him understand

some terminologies of the PSL, such as, Scale.

Since only one teacher participated in this study, this finding is very tenuous.

Findlng 9: Subject 23's case showed that the PSL helped him Ieam how to use an IBM
computer to collect experimental data and use the scale key to examine the
graphs for details. It seemed that the PSLs capability of allowing users to

repeat experiments very fast helped him understand the experimental data

and Ieam some terminologies such as Scale.

W

The nine research questions related to the impact of the PSL on Ieaming physics

were investigated by this study. The data were presented through nine research
questions. The findings in this study showed that the PSL had a positive impact on
Ieaming physics. This study also disclosed some areas which needed further research. A

summary of the study, implications, conclusions and recommendations are included in

Chapter V.

CHAPTER V

SUMMARY, FINDINGS AND RECOMMENDATIONS

This chapter summarizes the results of the three level procedures and the

findings of the research questions. Based on these summaries, various recommendations

are stated.

W

The subjects' activities were observed at three levels. They were: 1) Ieaming
how to use the PSL program, 2) applying the PSL program and 3) promoting creativity
for the usage of the PSL. Creativity here is defined as the process whereby subjects
were able to combine parts to form a unique or novel solution to a problem.

It is important to note that without teacher training, this technology won't

beused.

181

182

Table 5-1 Summary of the Results of the Three Level Procedures:

 

Using PSL

 

First Level:

Learning how to use the PSL
program.

The subjects' approaches
were verg similar.

Subjects learned how to use the PSL program:
Everg one followed the step- bg- step
procedures to perform the experiments.
All ofthe subjects successfully
completed three experiments. However,
they understood the results in different
degrees of sophistication.

 

Second Level:

Promoting application using
the PSL program,

The subjects‘ approaches

we re different in so me methods.

Subjects used the PSL program to:
Design their own experiments with
different set- ups ,- investigate the
experimental data in different wags and
understand the experiment results in
various depths.

 

Third Level:

Promoting creativitg using
the PSL program,

The subjects' interests and

Subjects combined parts within the PSL
or combined another program, such as

MS WORKS to form a unique or novel
solution to a problem. Their performances

reflected the depth of thinking.

 

approaches were verg different.

 

 

In this study, all the subjects completed the first level of Ieaming to use the PSL
program successfully and appeared to enjoy using it. In the first level, there did not
seem to be much difference between subjects' performance In following the step-by-
step procedures to complete the three temperature. experiments. However, their prior
knowledge of physics played an important role in determining their ability to explain
and / or understand the experiment. For example, in the temperature experiment,
almost all subjects realized the difference between blowing on a temperature probe and
blowing on their skins. Subjects who had no physics, however, were not able to explain
the reason for this difference. Subjects who had a physics background were able to

explain the difference logically.

183

It was interesting to note that subjects who had prior science knowledge
were eager to try the higher level two experiments. Subjects who did not have prior
science knowledge quit the experiment after level one.

In the second level, prior subject matter knowledge was ‘even more significant.
Subjects who had subject-matter knowledge concerning physics or mathematics were
able to design an experimental set-up in different ways and analyze the data with greater
depth and in more detail. For example, the two experimental set-ups designed by
subjects which related to the pH value and temperature experiment differed. Perhaps
this was because the eleventh grade subject understood Function (i.e. A function f from a
set X to a set Y is a correspondence that assigns to each element x of X a unique element y
of Y.) and the subject of ninth grade did not understand this concept. Another example, a
subject who had physics background discovered a more accurate way to measure the
period of the simple pendulum. As a result, this subject investigated the problem in
more depth than those subjects who had no physics background.

In the third level, subjects' interests differed greatly. Some were able to
combine parts of capabilities within the PSL program to form a novel solution. Other
subjects were able to combine MS Works with the PSL to form more novel solutions to a
problem. Their creativity reflected their computer experience, their subject-matter
knowledge and their desire to experiment with new ideas. For example, a subject who
had background in mechanical engineering was interested in finding equations to
represent the data obtained from the experiments. A subject who had a mathematics and
computer science background was more interested in using calculations. However, both

of them were able to combine different capabilities of the PSL program to solve the

problems.

184

The PSL program provided a new environment for scientific experiments. Its
sampling rate was very high, 34 times per second for the motion probe and 87 times per
second for the pH probe. Its measurements of distance and temperature were very
accurate (i.e. 0.50 millimeter for the motion probe, 0.05 degree of Celsius for the
temperature probe). After the subjects' experiments, the PSL automatically stored the
data in the computer and allowed subjects to analyze it graphically or by using the
calculation commands that the PSL program provided. In addition, the subjects
discovered that they could exchange data with MS WORKS.

The findings of this study indicated that the PSL program laid the foundation for
an excellent Ieaming environment. It had the following positive aspects that could
enhance physics education.

1) The PSL enhanced subjects' abilities to discover some challenging
phenomena with the use of computer graphs that were not available in
the traditional classroom lecture or experiments. For example, all
subjects discovered the difference between blowing on the skin and
blowing on the temperature probe. This difference was so minimal and
occurred so quickly that students would not likely to detect this
phenomena by using a regular thermometer. However, this conflict
engaged 30% of the subjects to think about ”why the temperature
seemed to be different between the skin and the probe“, 10% of them
formulated hypotheses for further Investigation. One high school
subject who had a physics background discovered the time difference
between two adjacent peaks. Her discovery could not be found by using
a regular stop watch.

2) The PSLs capability of integrating science, mathematics and computer

technology allowed subjects to repeat experiments several times

185

during a lab hour. Subjects utilized these capabilities to practice
some professional research skills. For instance, all subjects of
pendulum experiment discovered that, by repeating the pendulum
experiment using different lengths, the longer. that the pendulum
extend, the longer its period. One high school subject who had a
physics background even formulated two hypotheses and tested them.

3) Subjects who had strong subject-matter background with a strong
computer experience could perform some complex approximations
that they would not have been able to do in a traditional physics class.
For example, the engineering graduate student completed four complex
approximations for the experiments. His college course in physics did
not make this possible.

4) The immediate feedback, the reverse operations and the data presented
in both graphs and tabular forms provided a means for some subjects
from middle school and high school to understand the calculation
process. For example, the middle school and high school subjects
understoodADDACONSTANTandSUBTRACTACONSTANTbyappthg
ADD 2 and SUBTRACT 2 to the graphs.

5) The PSL provided understandable computer graphs for the subjects. It
enhanced their abilities _to view the experiment results from various
perspectives. For example, subjects viewed the experimental results
by telling about how and how fast each phenomena happened. They
were able to establish physical relationships from graphs. However,
subject-matter knowledge was needed in order to read some computer
graphs. The spring constant K in Figure 4-25 and Figure 4-26
demonstrates the need for subject-matter knowledge to better

understand its concept.

186

6) The PSL was a user friendly program. Subjects from middle school to
graduate level were able to use it. The graduate students even stated
that it was sophisticated enough to use for research. It provided an
opportunity for subjects at different levels to become successful in
physics education. In this regard, the PSL promoted motivation for
subjects at different Ieaming levels. For example, all subjects from
seventh grade to the graduate level were able to Ieam how to use the
PSL on their own and use it to perform the level one experiments.

7) The PSL provided an arena for students who had more computer
experience and more subject-matter background to explore the
experiments in greater depth. For example, an engineering subject
completed several complex approximations which he was not able to do
when he took physics in college.

8) The PSL supported and encouraged collaborative Ieaming for some
subjects. For example, subjects who worked together demonstrated
many benefits in solving mechanical problems and understanding the

experimental results.

I? .
This section discusses the research findings by comparing them with those found
by authors such as, Ronald K Thornton and David R. Sokoloff. The major foci of their
article was to investigate how effective the MBL was in teaching kinematics. Based on
their research, Thornton and Sokoloff concluded,
We believe that the following five characteristics of the MBL learning
environment-made possible by the tools, the curriculum, and the social
and physical setting-~are primarily responsible for the Ieaming gains.

1) Students focus on the physical world.

2) Immediate feedback is available.

187

3) Collaboration is encouraged.

4) Powerful tools reduce unnecessary drudgery.

5) Students understand the specific and familiar before moving to the
more general and abstract. (Thornton & Sokoloff, 1990)

The following comparison of the PSL program with the five characteristics of the
MBL which Thornton & Sokoloff concluded are that:

The comparison showed that subjects focused on the physical world while they
performed experiments with the PSL. For example, when subjects blew on the
temperature probe and their skin, about 30% of the subjects noticed the difference and
asked why. Some subjects formulated assumptions to explained the discrepancy.

In the temperature experiment, when subjects touched the temperature probe,
the computer graphs moved upward. Subjects understood that "moved up" on the
computer graphs corresponded to “temperature increase“ in the temperature
experiment. In the simple temperature experiment, when subjects saw the pendulum
move far away from the motion probe and the indicator of the distance on the computer
graph move up, they understood that “move up" on the computer graph corresponded to
“far away“ for the pendulum swing.

In this study, there was evidence of collaboration that certain attributes of the
PSL (i.e. understandable graphs and immediate feedback) seemed to encourage for some
subjects who worked together. However, some subjects who worked in pairs did not
show evidence of collaboration. The difference was probably due to the following facts:
1) Subjects in Thornton and Sokoloff's research project were students who were
enrolled in the Introductory physics class, they had the same interests--physics and
therefore had more in common. Subjects who collaborated in pairs in this study were
not enrolled in a physics class. Some stated that they were interested in the PSL
program itself and some stated that they were interested in scientific experiments which

the PSL initiated. 2) In Thornton and Sokoloff's project, research was conducted in a

188

regular introductory physics class and subjects were divided into groups of two to four
in the same physics class. However, subjects were not divided into groups in this study
(They were scheduled based on the time that was convenient for them). If a subject came
individually, he/she worked individually. If subjects came with someone, they worked
together in pairs. Some subjects who worked together were from the same grade, but
were not necessarily from the same classroom. Some of them were not acquainted. 3)
Thornton and Sokoloff's research project used a common curricula and their research
focused on a specific topic-the kinematics curriculum. For example, in the velocity
section of “Introduction to Motion", investigation one contained a number of exercises
using distance graphs. Students were asked to graph their velocities as they walked
quickly and slowly toward and away from the motion detector. They were then asked
questions about the graph's representations of fast, slow, away from, and toward.
(Thornton & Sokoloff, 1990). This PSL study did not use any specific subject-matter
curriculum to guide subjects' investigation because Ieaming specific subject-matter
knowledge was not the focus of this study. 4) Thornton and Sokoloff's research project
was a long-term research project. For the amount of time that the students used the
MBL to investigate the kinematics graphs, they probably would have known how to use
the MBL very well. However, subjects in this PSL study were first time users of the
PSL program. In the level one experiment, they Ieamed how to use the PSL program
while performing temperature experiments. Some subjects Ieamed the PSL quickly
while others Ieamed more slowly. Based on these facts, this author assumes that
subjects in Thornton and Sokoloff's research project had more in common than subjects
in this study. Yelu Yu's educational communication model could be applied to explain the
differences between Thornton and Sokoloff's findings and this researcher's findings.
(See Figure 1-1 in Chapter one for further information) In this situation, the

communications were between two subjects.

189

 

Figure 5-1 Subject A-subject B collaborative learning

In Thornton and Sokoloff's research project, subjects were enrolled in the same
physics class and the research was conducted for one semester or for one year. The
MBL's kinematics curriculum was incorporated into the subjects' physics class. As a
result, subjects had more common knowledge and experience and therefore collaborated
with each other more freely.

The understandable graphs and the immediate feedback seemed to encourage
collaboration for some subjects in this PSI. study. However, other subjects who worked
in pairs did not collaborate or at least did not seem to. Perhaps, it was due to the fact
that the overlapped portion of their common knowledge and experiences was minimal. If
a teacher were present and helped them to open up some channels of communication by
pertinent questions and guidance, the subjects who did not talk might have responded
orally. This would have increased collaboration. .

The results of this study supported Thornton and Sokoloff's conclusion that,
”Powerful tools reduce unnecessary drudgery." For example, the PSL helped subjects
save time in collecting, recording and analyzing data.

The results of this PSL study also supported Thornton and Sokoloff's conclusion
that, “Students understand the specific and familiar before moving to the general and
abstract.“ For example, in the simple pendulum experiment, subjects understood that
the pendulum moved back and forth and that each swing took almost the same amount of

time. As they continued to experiment with different pendulum lengths, they further

190

understood that each swing also took almost the same amount of time. In addition,
subjects further realized that the time interval of each swing related to the length of a
pendulum. This progression helped subjects move to the more general and abstract
concepts or principles.

Therefore, the results of this PSL study agree with Thornton and Sokoloff's
conclusions. However, since the subjects' backgrounds differed, the foci of the
researchers and the research methods differed. This PSL study made some new findings.
These new findings were:

1) The high sampling rate and the accurate measurement of the PSL program
created challenging phenomena for students from seventh grade to the graduate level in a
very simple temperature experiment. The experiment was simple, but the phenomena
was challenging. This implied that with the help of the PSL program, the same
traditional experiment could include some phenomena that students and / or teachers had
never seen before.

2) The PSL program haspotential capabilities that could assist students in
practicing some very professional research skills.

3) The PSL program provides new tools for students to do approximations which
they would not able to do using traditional methods.

4) Middle school and high scth students could take advantage of the PSLs
capabilities, such as immediate feedback, reverse operations and data presented in both
graphical and tabular forms, in order to understand the lntemal calculation process.

5) The PSL computer graphs assists students to understand the experimental
results from different perspectives.

6) The previous researches found that students from the sixth grade to the college
level were able to use the PSL. This study also invited graduate students to participate.
They used the PSL as an opportunity to Ieam more in-depth physics. Their

accomplishments in the PSL experiments caused them to believe that the PSL would be an

191

exciting intellectual challenge, particularly when they discovered some phenomena
which needed further investigation. Thus, their motivation to Ieam more about the PSL
increased and lead them to complete some complex approximations.

7) Previous research had found that the PSL supported and encouraged
collaborative Ieaming. However, this study showed that collaborative Ieaming was

evident in 45% of the groups who worked in pairs.

BecommendationsicLEunheLBessarcb
This study employed the PSL program's concepts in order to investigate the
impact that the MBL environment could have on subjects who were Ieaming physics.
The results of this study showed that the PSL program had a positive impact on subjects'
Ieaming of physics.

This study also disclosed some areas that needed further research.

Further Research 1: In the simple temperature experiments, the experiments were
simple, but the questions raised from the experiments were not
simple. For example, 1) Subjects who blew on the
temperature probe and blew on their skin found that the
temperature increased on the probe and their skin felt cool.
This phenomena challenged many of the subjects to think
critically. 2) Two subjects placed two temperature probes in a
water container and found that the two temperature probes
indicated two different temperatures. They were questioned
why this happened. 3) Some subjects found that the room
temperature in the lab was lower than the cold water from the

cold water faucet. This initiated some more important

192

questions dealing with what the role the teacher might play in
physics education:

a If a teacher were present and provided some guidances to
assist students, would it be possible for students in various
grade level to discover the cause of an effect and Ieam
something new about heat and temperature?

0 If some new phenomena of physics challenges not only
students but also the teacher, and the teacher is not able to
find a logical explanation, what will happen? Will this

discovery encourage or discourage teachers using the PSL?

Further Research 2: The PSL environment allowed students to collect and analyze
data quickly so that students were able to repeat the
experiments several times in the amount of time designated for.
a lab. The results of this study showed that some subjects could
explore, analyze, formulate hypotheses and test them in the
time allotted. This implies that the PSL program could be used
to create a Ieaming environment that students could use to
explore, analyze and build their own theories.

0 Would students receive more experience in research skills
and critical thinking if a new approach (i.e. students
explore, analyze and build their own theories by using the
PSL) is employed?

This question may seem very general. This author constructed ’
the following specific example in order to clarify this idea. It

illustrates the possibility of conducting this further research.

193

In this PSL study, subjects recalled that the simple pendulum
experiment gave the opportunity to investigate a theory they
had not studied previously. Based on the accurate data that the
subjects collected, they were able to formulate two hypotheses
and discover new ways to measure the pendulum period very
accurately with the help of the PSL analysis tools. Their
performance and results led this author to formulate a new
approach for students to Ieam the theory of the simple
pendulum through the PSL environment.
Briefly description of this new approach:
Traditionally, high school students usually Ieamed the basic
theory of the pendulum from the textbook first and perform
simple experiments to test the theory later. In the PSL
environment, students may Ieam the pendulum through
exploring, analyzing and building on a theory that they
generate. The research question for this example is, 'Can
students, with proper guidance and experiment, discover
mathematical relationships among various variables such as,
period (T), length (L) and the acceleration due to gravity (G)?
Specific procedures for this research are:
1. Students collect pertinent data for the simple pendulum by
using the PSL, then save the data for later use.
2. Students measure the variables of the period T, amplitude
A; and customize the wave so that the initial phase of the
wave is zero. They then export the data to a spreadsheet

and apply a formula to create a new set of data which

194

represents the real-time experiment data. Write down
this equation.

Some specific questions are raised for further research

here:

0 Will high school students be able to find an equation to
represent the pendulum wave they obtained from
experimentation?

- If they are able to find the equation to represent the data
they obtained, will they be able to explain how well the
equation represents the data?

- What types of research skills would students obtain in this
kind of approach?

Further Research 3: In this PSL study, a middle school subject explored the Fit-line
equation. The computer‘s Immediate feedback seemed to make a
great deal of sense to him. It is often very difficult for a middle
school student to understand the theory of the Fit-line equation.
However, this example suggested that it is possible for a middle
school student to apply this tool in order to analyze the
experimental data in the PSL environment, if appropriate
guidance and assistance are provided. One question is raised:

0 Would students be able to Ieam mathematics and science
(e.g. Fit-line equation) at an earlier age than was ever

thought possible, if the PSL environment were used?

195

Further Research 4: A graduate student who had both physics subject-matter and
computer background used the PSL very well; he completed four
approximation experiments. This was the first time the
subject had used the PSL. This implied. that the subject was
able to transfer prior knowledge which was learned from the
traditional approach to the PSL environment.

This raises another question by this author:

- Would a student be able to transfer the knowledge he / she
Ieamed from the PSL environment to a new situation (For
example, solving problems in the traditional textbook)?

This research question seems too general. A specific example
to pursue this research is recommended by this author:

The ideal graphs of Velocity vs. Time and Acceleration vs. Time
of the uniformly accelerated motion in two dimension are
straight lines. These led this author to formulate the following
experiment set-up to help high school students Ieam Newton's

Second Law through the PSL environment.

196

     
     

IBM computer

Small car
\ __________________
c Ultrasonic

\//////////////////////////// Measure the distance,

velocitg and acceleration
ofthe small car by using
the motion probe.

 

Motion probe I

 

\\\\\\\

ill'

IIL

\\\\\\\\\\\\\\\\\

Change the mass of the small car
by adding something inside in it.

x Change the force ofthe small car bu adding weights.

 

Figure 5-2 Exploring Newton's Second Law by using the PSL

This experimental set-up employs the motion probe to measure
the distance, velocity and acceleration of the small car. A
student might change the weights or the mass of an object in
order to explore the relationship between force and
acceleration. After collecting the data, students could use the
Reset Parameters. command to construct graphs of Distance vs.
Time, Velocity vs. Time and Acceleration vs. Time. Finally,
students could use the Fit-line function to discover equations
for Velocity vs. Time and Acceleration vs. Time. Some questions
derived from this suggested experiment for further research

are:

197

0 Does success on a computer-based experiment indicate that
a student has fully understood the concepts of force, mass
and acceleration and the reasoning (i.e. finding the
relationships of force, mass and acceleration) has
involved?

- Does practice in Ieaming basic physics concepts and
principles promote the development of scientific reasoning
ability, so that a student can reason successfully about new
situations (e.g. solving problems about Newton's Second
Law in the traditional textbook theoretically by applying

the concepts they Ieamed from the PSL experiments)?

Further Research 5: The question that follows emphasizes the connection between
math and the real world phenomenon. This outcome of the
question could enhance math Ieaming considerably.

One student raised an opinion which was very perceptive. This
subject stated: “The PSL can be used to teach mamematicsl'
The comment was based on the fact that the calculation process
was understood by dealing with the calculation commands
contained in the PSL capabilities. These capabilities were:
immediate feedback, interaction, reverse operation and data
presented in two forms, i.e. computer graphs and tabular
forms. This author recommends that the PSL be used to assist
students to Ieam: 1) Logarithmic functions through the
heating curves, 2) Concepts of derivative and integration

through the relationships among distance, velocity and

198

acceleration. 3) Graphs of the trigonometric function through
the graphs of the simple harmonic motion.

Jack M. Wilson succinctly stated that:

Selection of topics and indeed the physics sequence itself are
largely determined by the expected mathematical level of the
student. At the high school level, students are generally
expected to know trigonometry. In the introductory university
physics sequence, students are expected to start with a little
knowledge of calculus and develop more proficiency as they
advance through the sequence. (Wilson, 1990 p, 46)

In this study, there were participants who had taken
introductory analysis and others who had only completed pre-
algebra. This meant that even though the subjects were in the
same grade, their mathematical levels differed considerately.
This would naturally influence the way they approached a
physics experiment. Some of the subjects in the same physics
class in high school had very different mathematical
backgrounds. Some questions are raised here for further study.

0 Could the PSL be used to teach mathematics?

0 If the PSL could be used to teach mathematics, could the
PSL be used to bridge the gap between the abstract
mathematical concepts and the concrete physical
application?

0 Could the PSL be used to eliminate some Ieaming barriers

for students who had not taken the related mathematics

class and enable them to understand physics?

Further Research 6: The results of this study indicated that middle school and high

school subjects read the calculation changes from the table

199

better than reading the changes from the graphs (See research
question four). The results of this study also showed that the
PSL presented data in an understandable form; it helped
students to understand the subject-matter through different
perspectives (See research question five). The facts were: The
computer graphs that middle school and high school students
obtained in this PSL study were Temperature vs. Time, Distance
vs. Time and pH vs. Time. When they collected the data, they
saw the temperature, distance and pH value change on the
computer screen. The changing process of the experiment
helped the subjects understand the computer graphs. However,
when they applied a calculation command to the computer
graphs, they were not able to see the changing process because
the calculation worked behind the scene. Therefore, it took
considerable time for subjects to understand the changes. Some
problems remain for further research:

0 If a graph did not include time as a horizontal coordinate
(X-axis), for example, pH vs. Temperature or Intensity of
light vs. Distance, is it possible for middle school and high
school students to read and understand them easily?

- Further more, if a high school student chose Distance vs.
Velocity experiment set-up to perform a simple pendulum
experiment, will this student understand the graphs of
Velocity vs. Time?

0 Will a student understand the graphs of Acceleration vs.

Time?

200

0 How can the PSL be used better in order to help students
understand more complex and more abstract graphs?
- Does the student's ability to read the graphs relate to their

subject-matter knowledge?

Further Research 7: The results of this study indicated that students in level one
were not required to know anything about computer usage in
order to use the PSL. However, students did better in level two
and level three, if they had some prior computer experience.
Questions that need further research are:

0 Should a physics teacher also teach computer skills in
order to help students perform more complex physics
tasks?

0 Should teaching of computer skills become part of the
physics curriculum?

0 What level of computer skills are needed for physics

students?

Further Research 8: Thornton and Sokoloff's research project showed that the MBL
encouraged collaborative Ieaming in the regular physics
classes for the college level students. The results of this
study's observation indicated that some students who worked
together gained several benefits. These implied that the MBL
could be used to created an environment for students to Ieam
science through more project-oriented approaches. In the

projected-oriented approach, students are arranged in groups

201

and are directed to collect data, discuss the experimental
results and investigate challenging phenomena.

These questions therefore arise:

- Will students become more active'in Ieaming physics by
using the projected-oriented approach in the MBL
environment?

0 Will the MBL Ieaming environment encourage students
who are weak in physics to receive help from students who
are stronger?

- Will peer discussion help students understand the basic
concepts and rules in more depth?

0 Science research often needs teamwork. Will students get
training for teamwork through the projected-oriented

approach?

- Further Research 9: In the traditional physics education, “Even successful physics
students who can solve all of the problems at the end of the
chapter generally lack physical intuition.'...(Thornton, 1987
p. 231) 'In fact, laboratories are often omitted from or de-
emphasized in course because many laboratory instruments are
hard to use, fragile, unreliable and. expensive. In addition, the
teaching laboratory is not thought to be a place where students
can learn physics but a place for developing laboratory skills,
which are of limited academic usefulness."...(Thomton, 1987 _
p. 231) "Laboratories of this sort are better omitted from

courses because they discourage students, provide no new

 

202

information about nature and given an incorrect view of the
process of science." (Thornton, 1987 p. 231)

The results of this study, suggested that the PSL has the
potential capability to bridge the gap between theoretical
prediction and scientific experiment. In order to investigate
this capability further, this author recommends the following
experiment:

A dilemma facing the coffee drinker is to decide whether it is
better to add the cool cream to the hot coffee, stir, and let it cool
down, or to let the black coffee cool down first and then add the
cream.

To solve this dilemma theoretically involves making many
assumptions based on Newton's Law of cooling and the method of
mixture. Finally, it involves solving a differential equation.
(Greenslade, 1994)

Two scientific approaches could be applied to solve this
problem, one is deductive reasoning (from general to
particular) and the other is inductive reasoning (from
particular to the general). To solve the coffee cooling dilemma,
Greenslade applied deduction. It is difficult for a high school
student to explore this daily life problem in this way because
his / her limited mathematics background. With the help of the
PSL, it would be possible for a high school student to discover
the answer to this dilemma. By using Two-Temperature-Probe
experiment set-up they could compare which way the coffee
cools down faster. The questions raised for further research

are:

 

 

203

- Will the real-time data of the PSL match Greenslade's
theoretical prediction?

o If the PSL experimental results do not match Greenslade's
theoretical prediction, how might middle school students
explain it? Do students believe Greenslade's theoretical
prediction or their own experimental data?

- Is it possible that the use of computer-based experiments
to Ieam science might encourage routine application of
experimental data without enhancing ones understanding?

0 When students attempt to follow prescribed procedures,
will they think of the physics involved or will their
attention be devoted mostly to recalling and following
directions?

0 Could the PSL bridge the gap between theoretical prediction

and scientific experiment?

Further Research 10: The book W has been used in high school for
several years; this book allows students who do not have a good
mathematical background to Ieam physics. However, with the
help of the PSL, students would be able to obtain a great deal of
quantitative data. Knowing only the basic concepts of physics
is not sufficient for students to obtain more knowledge by using
the PSL. The current physics curriculum needs to be changed
in order to meet the needs of different levels of knowledge of
students.

0 What changes are needed?

 

 

204

Further Research 11: The findings of this study indicated that the ways subjects
used the PSL were related to their prior knowledge in science
and computing. That prior knowledge also helped them get the
most out of the PSL. Several research questions are raised in
this context:

0 Since seventh grade students were able to use the PSL very
successfully in this study and sixth graders were able to
use the MBL in the previous research, what is the
minimum grade level at which students can use the MBL
successfully?

- In this study, a ten-minute video (See Appendix A) was
effective in teaching subjects how to use the PSL. If
students lack prior knowledge, can they still use the PSL
package successfully with a tutorial program substituting
for a teachers help? What additional training materials
should be prepared to provide this kind of help?

- How can technology like the PSL and subject matter be
interwoven to provide needed prior knowledge to improve
curricula?

- In this study, this author had some opportunities to contact
some science teachers (Note: they were not subjects in this
study) informally in both middle school and high school.
They stated that they were interested in the MBL, but felt
that they needed training to keep up with the technology.
For example, a physics teacher had a PASCO's Science
Workshop (one version of the MBL) for several years, but

used only very simple applications in his physics class. He

 

 

205

said he did not have enough time to Ieam the new
technology. Do teachers need special training to providing
necessary prior knowledge to enable to students use the
MBL?

It seems as though there are many areas that need further research in order to

use the MBL environment more effectively and more efficiently in physics education.

5 I' I | . El . E! l' .”” ESI

The results of this study showed that the PSL program is an excellent tool for
learning physics.

1) The PSL could be used to demonstrate some challenging phenomena which
students could not see without using the PSL. This study provided two phenomena to show
this PSLs capability: one was the difference between blowing on skin and blowing on
temperature probe. Another was the different time intervals between two adjacent peaks
of a pendulum. In his article, "Tool for Scientific Thinking---Microcomputer-Based
Laboratories for Physics Teaching“, Ronald Thornton stated that, “Such instruments not
only extend the kinds of phenomena that can be investigated, they also measure
phenomena over time-scales that are both shorter and longer than can ordinarily be
conveniently used. Temperature variations can be measured over days to study diurnal
temperature cycles and weather changes, while sound pressure waves are easily
measured and displayed over milliseconds.” (Thornton, 1987)

2) With the combination of MS WORKS spreadsheets, the PSL could be used to
compare the scientific experiment data with the theoretical prediction. This is because
the PSL allows students to collect real-time experimental data, store data in a computer _
for later analysis and exchange data with spreadsheet programs. (See research questions
3 & 4 in Chapter four for more details) On the other hand, spreadsheets allows students

to input formulas easily in order to experiment with theoretical simulations. (See the

206

role of computer simulation in physics education in Chapter two for details) The
approximations that the engineering graduate student completed demonstrated this PSL
capabflfiy.

3) Some guidance materials could be developed in order to assist and encourage
students to do further investigation for depth in the PSL experiments. The challenging
phenomena that the simple temperature experiment created in this study suggested this
need. Thornton & Sokoloff's research findings (1990) also showed that the MBL tools
were not enough, the combination of the tools and the appropriate curriculum materials

were needed.

mm

The MBL opens up a new arena for physics education. In this study, the more this
researcher observed students using the PSL, the more possibilities of using the PSL
program derived. This study also suggested several areas that needed further research.
This author believe that the IPSL will play an important role in physics education.

Finally, this author would like to use the word processing program as an analogy
to predict the future for the MBL. The word processing program is not a teacher of
writing for this author. However, the word processing program helped this author edit
text faster, easier, and more accurately so that he did not have to be concerned about
spelling and grammar errors because he could make changes at any time. This author
used these capability to focus on how to better organize ideas and data. This author found
the word processor to be an excellent tool. Elementary school students are able to use it
in their writing classes; the university professor can use it to create materials for
teaching and for research reports. The MBL is not a subject-matter teacher, but it
certainly could help students do experiments and research faster, easier and, perhaps, it

would promote more in-depth Ieaming. This author believes that middle school students

207

would be able to use the MBL for learning physical science, while graduate students

would probably like to use it for Ieaming physics and doing research in the future.

 

APPENDICES

 

APPENDIX A

The Storyboard of Introductory Video of the PSL

INTRODUCTION

 

The IBM Personal Science Laboratory

(PSL) is a flexible and powerful

 

microcomputer-based laboratory. PSL
consists of hardware and software, which
works together to provide the science
Ieaming experience. It can be used for
physics, chemistry, biology, and

Mathematics.

 

 

mputer

if j HARDWARE
Co

The hardware for PSL consists of the

 

 

 

 

Communication ' .
Cable , — . followrng components:

  

208

209

 

 

 

 

 

 

 

 

 

Q 1. Any IBM personal computer with a
serial port.
3 a I: I-
\la—am

 

 

Base Unit _.. --

   
 
  
 
 
 
 
  
  

2. The hardware for PSL Base Unit is the
hub of PSL hardware, it controls

multiple probes at once.

3. Modules can be inserted into any port

Temperature, Light and
PH Module

module.

(2) Motion and Mechanics Module.

 

Motion &Mec ha nics
Module

210

4. Sensor devices can be inserted into the
related modules. There are four types

Extended of probes:
(1) Temperature probe can be used to

Standard
collect data about temperature.

    
 

(2) Light Probe can be used to collect

data about the intensity of light .

(3) pH probe can be used to collect data

about the pH scale of a liquid.

(4) The Distance Probe uses ultra-
high-frequency sound to detect the

distance.

Motion &Mechanics
Module

211

EXPLORER

Select 9 1p. lira-ate e 4p. ["lfl’

 

 

 

Main Menu

 

 

 

 

 

 

Analg sis Menu

 

 

SOFTWARE

The software supplied with PSL consists of

the PSL EXPLORER. It provides menus for

the user to control PSL.

PSL EXPLORER is comprised of three

sequential menus:

1. The Main menu is displayed when PSL
EXPLORER is started. It allows users to
select the existing experiment setups

or create their experiment setups.

2. This Run menu is displayed after the
user accepts an experiment setup. It
allows user to perform his or her

experiment.

3. This Analysis menu is displayed when
the collecting of experiment data is
completed. The results of the
experiment appear as a graph which
this menu enables the user to analysis

the data.

 

 

 

212

AN EXAMPLE OF USING PSL

 

--- Mass and Spring experiment

This demonstration which shows how to

 

 

perform a Mass and Spring experiment
step-by-step:

Step-1: Set up the equipment like this.

 

 

0’ Step-2: Start the software by typing PSL
c\:PSL

 

and press Enter key. The Main

Menu will be displayed.

 

 

 

 

 

 

 

 

 

 

 

Select. e::-::p. Create exp,

Step-3: From the Main Menu, highlight

Cine Ternp .v: .T
T a F' r stu. Tu

select experiment and press

 

Enter key. A small window

appears.

 

 

Main Menu

213

   
 

   

[1' I E Iii

 

   
 
 

'Eelecd ewIL IZreate earn
Cine T ernp -.-: .T
T o F' r o t- . Tu

Dist.vs. 'v'el.

 
    
  
 

Main Menu

 

  
 

    

Fl =Help Fl III=IZIIJit

 

 

 

 

II III 1! '
Run Menu ......

 

 

Step-4: Press the down arrow key to
move the highlight to Distance
and Velocity and press the Enter
key in order to select the setup

of Distance and Velocity.

Notice that the screen has been changed

from Main Menu to the Run Menu.

Step-5: As the Run Menu is displayed,
the experiment is ready to run.
Highlight Run experiment and

press Enter key.

When the first small window is
displayed, highlight Calibrate...
and press the Enter key. When
the second small window is
displayed, highlight Distant...
and press the Enter key. When
the third small window is
displayed, use Arrow and the
Enter key to change the Air

temperature and Data rate.

214

Step-6: Press ESC key twice to hide the

second and the third small

 

windows._
Step-7: From the first small window,

I move the highlight to Start. Now
II It

 

 

it is ready to collect data.
'r- Step-B: Start the Mass and Spring
Oscillation.
Step 9. Press the Enter key to start
collecting data.
As soon as the collecting data is
completed, the screen will be

changed from the Run menu to

 

the Analysis Menu.

 

This signifies that the program is
ready to analyze the data you have
been collected.

a I-IWWI— "flu“- Step-10: Press the F4 key to scale the

upper graphic.

 

Step-11: Press the F2 key to switch the

 

frame to the lower graphic and

press the F4 key to scale it.

 

 

 

/— Hightlight Graphic

Graph Reset. par. II:al:::ulate Table [his-l:

 

215

Step-12: Highlight the Graph on the top
menu bar and press the Enter
key. Move the arrow by
pressing the arrow key to the

place you wish to see the

details.

 

 

 

Graph Reset par, Calculate Table [3131:

 

 

I." ‘-

 

 

 

 

Step-13: Press the M key and arrow key
to mark the area you wish to
see details. Then press the 2
key. A small window will be
displayed.
Step-14: Highlight Zoom-in to marked

region and press the Enter key.

Step-15: To perform the calculation
analysis, press the ESC key.
Move the highlight to calculate
on the top menu bar then press
Enter key. A small window

will be displayed.

Graph Fla-set. par. Calculate Tat-1E- [III-air:

 

 

 

 

 

E- u rn mar y :

First ..... Main Menu

Second....Run Menu

Third... Analysis
Menu

 

 

 

 

 

 

 

 

 

 

 

 

 

216

Step-16: Move the highlight to Y-axis...
and press the Enter key. As
the second small window
appears, select the calculation
you want to perform the

calculation.

SUMMARY
First: Using Main Menu to select or
create your experiment set-up.

Second: Using Run Menu to calibrate
and start collecting data.

Third: Using the Analysis Menu to
analyze data.

For further information, read Reference

Guide to find the information you need.

GOOD LUCK I

217

APPENDIX B

Survey Questionnalre

Questionnaire One: Items about computer experiences
May I personally assure you that all your responses will be dealt with complete
confidence and any writing on this subject by me will contain no references to
individuals or schools.
(1) Have you ever used a computer ?
at school
at university
in employment
at home ( including games )
other
(2) Can you
load a program
use a program that has been loaded
write a program
connect up a keyboard / monitor / printer
(3) How confident are you about using
hardware
software (computer game, word processing, data base,
spreadsheets, statistical analysis software, math
science and engineering software)
(4) How confident are you feel about using a computer ?
personally
as a Teacher
(5) How many hours per week do you spend using a computer ?

less than 2 6-10 over 15

 

218

2-5 __ 11-15 __
(6) Have you ever taken computer course in school for credit ?
Yes _ NO __
(7) If so, how many hours credit have you received ?
1-3 __ 7-10 __
4-6 __ over 10 __
(8) Have you ever had in-service training designed to improve Your
computer instruction ?
Yes No

— —

(9) How would you rate your level of computer expertise ?
high above average below low
average average

Thank you very much for your help.

Questionnaire Two: Items about subject-matter knowledge
May I personally assure you that all your responses will be dealt with complete
confidence and any writing on this subject by me will contain no references to
individuals or schools.
(1) Have you ever taken the following science courses in Middle
SchooVHigh School forcredit ?

Science Algebra II Analysis

 

 

Physics Chemistry Biology

 

(2) Have you ever taken the following science courses in college for
credit ?

Physics Chemistry Biology

 

(3) What science courses have you taught in school ? ( For teacher only )

Thank you very much for your help.

219

Questionnaire Three: Items about attitudes measured on a 5-point scale of
agreement or disagreement (For teacher only)

May I personally assure you that all your responses will be dealt with complete
confidence and any writing on this subject by me will contain no. references to
individuals or schools.

(1) I would like to Ieam more about computers as teaching aids.

(2) I don't mind Ieaming about computers.

(3) I could (can) well do without the aid of a computer in my class. I

(4) Working with computers in class distorts the social climate.

(5) Computers harm relations between students and teachers.

(6) Computers are valuable tools in improving the quality of a child's
education.

(7) Computers can only be useful in a few subjects.

(8) Using a computers in a school enhance students' creativity.

(9) I am interested in using computers in lessons.

Thank you very much for your help.

 

220

APPENDIX C
RESEARCH SITES

The diagram of the research site In the ,high school:

Computer Lab (Next door)

 

 

 

 

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Hall wag

Observer

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—l —‘ —‘ ‘_'

 

 

I Entrance ——>

 

Physics Lab (Next door)

221

The dlagram of the research site at Michigan State University:

 

 

 

Entrance

 

 

 

 

 

 

 

 

 

 

Entrance

.lIIIIl. 0b“”‘*'
Hall way

 

 

222

The diagram of the research site In the middle school:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

o
8
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E ”The PSL H
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Science Lab Two Teacher's Subject
Computer 0
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___ ............

 

 

 

223

APPENDIX D

SAMPLE EXPERIMENTS

This appendix contains three sample experiments and one sample exploration.

The sample exploration is taken from Personal Science Laboratory Temperature
Experiments, Version 1.00.

These activities will teach you how to set up and run your PSL hardware and your
PSL Explorer software.

Note: These sample activities can be photocopied and distributed for use only
within the school that purchased the PSL Explorer program.

Activity 1: A Simple Temperature Experiment

This activity guides you in choosing and running a one-probe temperature
experiment from the list of experimental setups. This is the easiest way to

perform an experiment using PSL Explorer and provides a good introduction to
the program.

Set Up and Run the Experiment

1. Set up the PSL equipment by doing the following:
a. Insert the blue Temperature, Light, and pH(TLp) Module into any of the
four ports on the PSL Base Unit.
b. Insert the Standard Temperature Probe into channel 1 of the TLp Module.
(The Standard Temperature Probe is the one with the small metal chip on

the end; the Extended Temperature Probe is the one with the long metal
rod.)

2. Start the PSL Explorer program.

Refer to "Starting Software" on page 1-2 for instructions on starting the
software.

3. After startup, the Main Menu is displayed on your computer's screen.

224

Select experiment Create experiment

MAIN MENU

FIOZOUit

 

Figure D-I. Main Menu

Choose Select experiment from the Main Menu by doing the following:

a. Use the Left and Right Arrow keys to highlight the Select experiment option
at the top of the Main Menu.

b. Press Enter. The window that is displayed contains a list of the
experimental setups included with PSL Explorer:

Heat of Neutralization
Two Probe Light Pendulum
One Temperature vs. Time
Angle of Polarization
Harmonic Motion
Standard Titration

More

4. Use the Down Arrow key to highlight One Temperature vs. Time and press
Enter. The screen that is displayed includes almost all the information you
need to run your experiment.

_t'
V: 1’
LI -. m. ‘

 

 

 

225

Reset Parameters Run experiment

One Temperature vs. Time Temp A vs Time.

 

 

2o.oo
nun MENU

Fl=Help F2=Svitch F3=Split F8=Accept F9=Restart F10=0uit

 

Figure D-2. One Temperature vs. Time Setup Screen

5. Highlight Run experiment and press Enter. The following window will be
displayed Select action

Start
Calibrate...
Preview...
View...

6. The next step is to calibrate the temperature probe. Each PSL temperature
probe has a label on which you will find a three-digit calibration number. This
number adjusts the PSL Explorer program for the slight variations that are
normal between probes.

a. Use Down Arrow key to highlight Calibrate... and press Enter.

b. Highlight Temperature and press Enter.

0. Highlight Probe A calibration: 500 and press Enter.

d. Enter the three-digit number found on the cable of your temperature
probe. (If there are only two digits add a zero to the end.)

e. Press Enter.

1. Press Esc.

9. Press Esc again to return to the Select action window.

h. Use the Up Arrow key to highlight Start and press Enter.

226

Look at the graph on the screen. The line being drawn across the screen
indicates that your computer is measuring the temperature of the room.

7. Let the experiment run for about 15 seconds to establish a graph of room
temperature, then touch the probe, wave it in the air, or blow on it and
observe the results on the screen. _

0 Does the temperature increase or decrease when blow on the probe ?
0 Is this different from you feel when you blow on your skin ? Why ?

8. When the experiment is finished, press F9 to restart the program. The
following window will be displayed:

Discard experiment data?
M)
Yes

Highlight Yes and press Enter to discard the experiment.

Activity 2: Creating an Experiment

In this activity, you will choose the type of experiment you want to conduct, set
up the parameters, collect the data, save the results, and perform some simple
analyses of the data.

Set Up the Experiment

1. Set up the PSL equipment by doing the following:
a. Insert the blue TLp Module into any of the four ports on the base unit.
b. Insert the Standard Temperature Probe into channel 1 of the TLp Module.

2. Start the PSL Explorer program.

Refer to “Starting the Software" on page 1-2 for instructions on starting the
software.

3. Select the Create experiment option from the Main Menu by doing the
following:

a. Use the Left and Right Arrow keys to highlight the Create experiment
opfion.
b. Press Enter. The following menu is displayed:

227

Distance Temperature Light PHfthermister Time Kegboard

Time vs Time

 

 

20 .00

CREATE MENU
F1=Help F2=Svitch F3=Split F5=Print F8:Accept F9=Restart F10=Ouit

 

Figure D-3. Create Menu

. Highlight Temperature and press Enter.
. Highlight Temp A and press Enter.

. Highlight Y-axls and press Enter.

VOW-k

. Press F8, highlight Yes, and press Enter to accept the setup. The Tun Menu
will be displayed.

8. Highlight Reset parameters and press Enter. The following window will be
displayed: '

Select parameter
Axis variables...
Duration...
Labels...

Numeric format...
Ranges of axes...
Type of plot...

228

Do the following to define the parameters for the experiment:

a. Highlight Duration and press Enter.

b. Type 70 for the experiment's duration and press Enter. The Select
parameter window will disappear and Reset parameters will be
highlighted.

Press Enter.

. Highlight Ranges of axes and press Enter.

. Highlight Y-mln (Temp Aln C) field will be highlighted.

. Press Enter.

i. Type 100 for the maximum (Y-max) value and press Enter.

j. Press Esc to return to the Run Menu.

3'on

9. Before you begin collecting data, it is very important to save the experimental
setup you just created so that you can use it again later. You can save the setup
by doing the following:

a. Highlight Disk and press Enter.

b. Highlight Setup and press Enter.

c. Insert a formatted diskette into drive A. Do not use your PSL Explorer
diskette to save your experiments.

d. Press the Insert key.

e. Type a name for the setup; the name you type can be as many as eight (8)
characters in length and should be a name that you will recognize later.

f. Press Enter.

Note: If the message Disk [d] is write-protected is displayed, you must
removed the diskette from the drive, locate the lab at the bottom of the
backside of the diskette, and slide the tab up. Your diskette is no longer
write-protected and you should be able to save your experiment setup.
Otherwise, use another formatted diskette that is not write-protected.

9. Type a description of the setup; the description can be as many as 25
characters in length and should be a description that will easily identify the
setup.

h. Press Enter.

Run the Experiment

1. Fill a 100-mL beaker one-third full with cold water, then fill a second 100-
mL beaker one-third full with hot water.
Note: The results you obtain from this experiment will vary depending upon
the amount of water you use In the beakers.

2. Place both beakers close to the PSL equipment.

3. Highlight Run experiment and press Enter. Now, you will calibrate the
temperature probe by doing the following:

a. Highlight Calibrate and press Enter.

b. Highlight Temperature and press Enter.

c. Highlight Probe A calibration: 500 and press Enter.

d. Enter the three-digit number found on the cable of your temperature probe.
(If there are only two digits, add a zero to the end.)

e. Press Enter.

f. Press Esc twice to return to the Select action window.

229

4. Hold the temperature probe by the plastic wire. Do not touch the metal probe
itself.

5. Highlight Start and press Enter. Look at the graph on the screen. Your
computer is now measuring the temperature of the room.

6. After 10 seconds, place the temperature probe into the beaker of cold water.
Watch the screen and notice the program's response to your action.

7. Leave the probe in the cold water for 10 seconds then remove it from the
beaker of cold water. Use a tissue to dry the probe, then hold it steady without
moving it.

8. After 10 seconds, place the probe into the beaker of hot water. Watch the
screen to see the program's response.

9. Leave the probe in the hot water for 10 seconds, then pour the cold water into
the beaker of hot water.

10. After 10 seconds, press Esc to end the experiment. The Analysis Menu will
be displayed when the experiment is completed. This menu allows you to
manipulate the data you have collected.

Save and Analyze the Data

Some of the options on the Analysis Menu allow you to change the data you just

collected. Always save your collected data before using the Analysis Menu. Save

the experimental data you just collected by doing the following:

1. Select Disk and press Enter.

2. Select Data and press Enter.

3. Press the Insert key.

4. Type a name for the data; the name you type can be as many as eight(8)
characters in length and should be a name that you will recognize later.

5. Press Enter.

6. Type a description for the data; the description can be as many as 25
characters in length and should be a description that will easily identify the
data.

7. Press Enter.

8. Press Esc twice to remove the windows.

To analyze the data collected by the experiment, do the following:

1. Highlight Graph on the Analysis Menu and press Enter. Notice that an arrow

appears on the graph; you can move this pointer with Left and Right Arrow
keys.

 

 

 

 

230

2. Use the Right Arrow key to move the pointer to the place on the graph where
you put the probe into the cold water.

3. When the pointer is at the beginning of the cold water measurement, type M to
begin marking a portion of the graph.

4. Use the Right Arrow key to move the pointer to the place on the graph where
you took the probe out of the cold water. Notice that the graph is highlighted as
you move the pointer.

5. When the pointer is at the right place, type F to display a window that will
enable you to draw the best-fitting straight line for the marked area of the
graph. The equation of the line will be displayed in the upper-left comer of the

graph. The slope of the line measures the average rate of cooling for the
marked area. '

6. To enlarge a particular area of the graph for closer examination, type M again
to begin marking an area.

7. Move the pointer to the end of the area you want to examine, then type 2 to
enlarge the marked area of the graph.

Quit and Rerun to the Main Menu
1. Press Esc to leave the Graph option.
2. Press F9 to return to the Main Menu. The following window is displayed:
Discard ex'pgriment setup ?

Yes

3. Highlight Yes and press Enter. The Main Menu is displayed.

Activity 3: Selecting and Running a Two-Probe Experiment
In this activity, you will select a pre-defined experiment and then run it. The
experiment you will run uses two temperature probes to collect data. When you
run the experiment, the data from the probes will be displayed on two graphs;
one for each of the probes.

Set Up the Experiment
1. Plug the Extended Temperature Probe into Channel 2 of the TLp Module.
2. On the Main Menu, highlight Select experiment and press Enter.
3. Highlight Two Temperatures vs. Time and press Enter.

4. Fill a 100-mL beaker one-third full with cold water, then fill a second 100-
mL beaker one-third full with hot water.

231

Note: The results you obtain from this experiment will vary depending on the
amount of water in the beakers.

5. Place both beakers close to the PSL equipment.

6. Place probe A in the beaker of cold water, then place probe B in the beaker of

hot water.

Run the Experiment

1.

Highlight Run experiment and press Enter. The following window will be
displayed:

Start
Calibrate...
Preview...

View...
I

You have already calibrated the first temperature probe. Now, you will calibrate
the second temperature probe by doing the following:

2.

a. Highlight Calibrate and press Enter.

b. Highlight Temperature and press Enter.

c. Highlight Probe B calibration: 500 and press Enter.

(1. Enter the three-digit number found on the cable of the temperature probe.
(If there are only two digits, add a zero to the end.)

e. Press Enter.
f. Press Esc twice to return to the Select action window.

Highlight View to confirm that the probes are in the correct locations. Temp A
should be in Port 1, Channel 1; Temp B should be in Port 1, Channel 2.

. Press Esc.

. Highlight Start and press Enter. Notice that two graphs are being plotted

simultaneously on the screen. Your computer is now measuring the
temperature of both the hot water and the cold water.

. When the experiment is complete (or when you press Esc), the Analysis Menu

will be displayed. You will notice that the lower graph is framed by a box.

. Press F2. The box framing the lower graph will now move to the upper graph.

The graph with the box around it is the active graph. When you perform the
peorations that are available on the Analysis Menu, they will effect only the
active graph.

. Highlight Reset Parameters and press Enter. The following window will be

displayed:

Select parameter
Axis variables...
Duration...
Labels...

232

Numeric format...
Rangesofaxes...
Type of plot...
8. Highlight Labels and press Enter.
9. Highlight Y-axls name and press Enter.
10. Type probe A and press Enter.
11. Highlight Y-axls units and press Enter.
12. Type deg C and press Enter.

13. Press Esc to remove the window. Notice that the changes you made affected
the y-axis of the top graph only; the lower graph is the same as it was.

14. Press F2 to switch the box to the lower graph.

15. The highlight bar will be on Reset Parameters. Press Enter. The Select
parameters window will be displayed again.

16. Highlight Range of axes and press Enter.

17. Highlight Lower: y-mln (Temp B In C) and press Enter.
18. Type 0 and press Enter.

19. Highlight Lower: y-max (Temp 8 In C) and press Enter.
20. Type 100 and press Enter.

21. Press Esc to remove the windows. Notice that the changes you made affected
the y-axis of the lower graph only.

Save and Analyze the Data
Save the experimental data you just collected by doing the following:
1. Select Disk and press Enter. ‘
2. Select Data and press Enter.
3. Press the Insert key.

4. Type a name for the data; the name you type can be as many as eight (8)
characters in length and should be a name that you will recognize later.

5. Press Enter.
6. Type a description for the data; the description can be as many as 25

‘ characters in length and should be a description that will easily identify the
data.

233

7. Press Enter.

8. Press Esc twice to remove the windows.

234

APPENDIX E
INTERVIEW QUESTIONS
M

Activity 1:
a After activity 1, do you get the general idea about how to use an already existing
experiment set-up to perform an experiment? How?
0 Answer the two questions in Step 7?
1) Does the temperature increase or decrease when you blow on the
probe?
2) Is this different from what you feel when you blow on your skin?

Why?

Activity 2:

0 What is the difference between Activity 1 and Activity 2?

- What big change did you see about the menu after you completed the Step 7 in
Set Up the Experiment?

- What big change did you see about the menu after you completed the Step 10 in
Run the Experiment?

0 After activity 2, do you get the general idea about how to create your own
experiment set-up to perform an experiment? How?

- What did you find from the data in this experiment?

Activity 3:
- In Step 2 in Run the Experiment, why is it necessary to highlight View to see
the locations of each probes? Is this step necessary in Activity 1 and Activity

2? Why or why not?

235

o In Step 4 in Run the Experiment; If a person pulls out both Temperature
Probes (one in the hot water and the other in the cold water) at the same time

after 10 seconds, what happens on the computer screen? How do you explain

this result?

0 How do you think about PSL?

0 What factors affect the period of the simple pendulum?
- If the clock goes faster in the Winter, how will you adjust it?
0 If the clock goes slower in the Summer, how will you adjust it?

- What do the new computer graphs mean when you choose a calculation function

In the PSL?

LmLJhr.»
0 What Is the theoretical foundation of this approximation?
0 Could you state the strategy that you used in finding the approximation equation
this way?
0 Do you feel confident that the approximation equation you obtained adequately
represents the real-time data you had collected? Why?

0 Do you feel confident when you use the calculations in the PSL program?

236

APPENDIXF
ADDITIONAL INFORMATION ABOUT THE MBL

W is a good source of updated information about the PSL.
Presently, several companies have advertised new versions of MBL. They are:

1) Kis interface-~the former PSL

2) PASCO'S Science Workshop

3) Calculator-Based Laboratory--this version uses a graphic calculator called

Tl-85 (around $99 in the market)

Some schools may lack the funds for new computers on which to use the PSL
package. An alternative can be using old computers. This author tried the PSL package
on a very old IBM compatible computer (Zenith) now available at Michigan State
University's salvage for $35 (included monitor and keyboard). This computer had only
640K of RAM, and no hard disk drive, only two 5 and 3/4 inch floppy drives. When the
PSL software called EXPLORER were separated onto two 5 and 3/4 inches floppy drives.

It ran perfectly.

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