The Need to Prove


TABLE OF CONTENTS


Frontispiece
ii
Title page
iii
Dedication
v
Abstract
vii
Acknowledgements
ix
Figures & Tables
xiv
 

INTRODUCTION

1
A note on transcripts and diagrams
4
CHAPTER I: PROOF AND PROVING 6
1. What is proving?
6
What is proving in school mathematics? 7
What is proving for professional mathematicians?
8
 2. Why do people prove?
10
Why do mathematicians prove? 10
Proving does not always verify 11
Other ways mathematicians verify
13
 Why do students prove?
14
Do students prove?
14
Uses of proving
15
Researching the need to prove
17

CHAPTER II: NEEDS AND PROVING

21
1. Explaining
24
Explaining – Formulated proving – Preformal proof
25
Rachel and Eleanor explain the formulae found inthe Arithmagon situation
25
Ben’s formulated proving to explain to others
27
Colin and Anton explain the origin of their Arithmagon formula
28
Colin and Anton’s formulated explanation that n3 - n is a multiple of 6
29
Bill and John’s explanations by formulated proving
30
 Explaining–Unformulated Proving
32
Kerry’s short explanation 32
Ben’s unformulated explaining to others
33
Bill’s unformulated explanation that F3nis even
34
 Explaining–Analogy
35
Bill’s explanation by analogy 35
Rachel, Ben and Wayne attempt to explain "Why 2?"
36
 Summary
38
2. Exploring 
39
Exploring – Unformulated proving
39
Bill’s unformulated exploration
40
Sandy’s formulation of his unformulated proving to explore
40
 Exploring – Formulated proving – Preformal proof
41
Rachel’s explorations by formulated proving
42
Eleanor’s explorations by formulated proving
43
 Exploring – Mechanical Deduction – Preformal proof
44
Exploring – Analogy
45
Exploring – Inductive reasoning
46
Summary
47
3. Verifying
49
Verifying – Unformulated proving
48
Verifying – Mechanical deduction – Preformal proof
49
Verifying – Inductive reasoning
50
Verifying – Authority
50
Anton’s reference to authority 51
Bill’s rejection of analogy, induction, and deduction in the face of authority 
51
Verifying in school
52
 Summary
52
 4. Teacher-games
52
Teacher-game/Verifying – Formulated proving
53
Colin verifies a particular case by reference to formulated proving 53
Kerry proves to verify that F3nis even
54
 Teacher-game/Verifying – Formulaic proof making
54
Summary
55
5. Synthesis
56
Verification
56
Explanation
57
Exploration
57
Teacher games and other social contexts
58

CHAPTER III: KERRY, STACEY AND THE ARITHMAGON: REASONING IN ACTION

59
1. Mechanical deduction to explore
59
2. Unformulated proving to explore
60
3. Mechanical deduction to explore
61
4. "Generalizing"
62
5. Inductive and deductive exploring
62
6. Inductive reasoning to explore
66
7. Unformulated proving to explore
67
8. Reasoning by analogy to explain
67
9. Inductive reasoning to explore
68
10. Reasoning by analogy to explain
69
11. Further exploring
70
12. Formulated proving to explain, interpreting a semi-formal proof
70

CHAPTER IV: CONSTRAINTS ON PROVING

72
1. Individual Differences
72
Summary 74
2. Social constraints
75
Eleanor and Rachel
75
Rachel
75
Eleanor
76
 Bill and John
77
3. The prompts
77
Arithmagon
77
Fibonacci
78
GEOworld
79
Summary
79

CHAPTER V: TEACHING PROVING

80
1. Proving in the Curriculum
80
Alberta
80
The Standards
82
2. Current practices in teaching proving
83
Schoenfeld on teaching for examinations
83
Teaching at North and South Schools
84
 3. Experiments in teaching proving
85
Fawcett’s research
85
Research by Balacheff et al.
87
Research by Lampert in the United States
88
Weaknesses of teaching based on the courtroom metaphor
88
4. Speculations on improving teaching
89
5. Why teach proving?
92

CHAPTER VI: PROVING IN SOCIETY

95
 1. What is Rationalism?
95
2. Rationalism’s Weaknesses
97
Deduction and Absolute truth
97
Significance of Gödel’s Theorem outside ofmathematics
100
Rationalism is not universally applicable
103
Dangers of misapplied Rationalism 104
 3. Rationalism and other modes of thought
106

CHAPTER VII: REASONING AND RESEARCH FROM AN ENACTIVIST PERSPECTIVE

110
 1. Enactivism
110
2. Enactivism and reasoning
114
3. Enactivism and research
119
Basic principles
120
Some specifics
121
 4. A few parting words on Enactivism, proving, and teaching
122
REFERENCES 124

APPENDICES

A: RELATED LITERATURE

132
 1. Other publications by researchers referenced in the main text
132
2. Discussions of the nature of proof in mathematics
134
3. Research on students’ understanding of the conceptof proof
134
4. Useful literature reviews
136
B: DESIGN AND DÉROULEMENT OF THE RESEARCHSTUDIES 137
 1. The North School study
137
Context
137
Outline
137
Participants
138
 2. The South School study
138
Context
138
Outline
139
Participants
139
 3. The first clinical study
139
Context and outline
139
Participants
140
 4. The second clinical study
140
Participants
141
5. Other Studies
141
Sandy
141
Central High School
141
 6. Methods
141
7. Prompts
142
Arithmagon
143
Fibonacci
143
GEOworld
144
C: MATHEMATICAL ACTIVITY TRACES 146
 1. MATs from the study at North School
146
Mathematical Activity Traces for the Math 13 Pair, Bill & John 
146
Fibonacci 146
Arithmagon
148
First Interview
150
Second Interview
153
 Mathematical Activity Traces for the Math 30 Pair, Colin & Anton 
155
Fibonacci 155
Arithmagon
157
First Interview
159
Second Interview
161
 2. MATs from the first clinical study
163
Group I: Ben and Wayne
163
Arithmagon 163
 Group II: Stacey and Kerry
166
Arithmagon 166
Fibonacci
168
 Group III: Eleanor and Rachel
169
Arithmagon
169
Fibonacci
172
 Group IV: Jane & Chris
173
Arithmagon 173
 D: TABLES OF RESULTS 175
 1. Needs and proving in different problem situations
175
2. Needs and proving by different participants
176
3. Needs and proving for individual participants
177
First clinical study
177
Ben 177
Wayne
177
Stacey
178
Kerry
178
Eleanor
179
Rachel
179
Jane
180
Chris
180
 North School study
181
Bill 181
John
181
Colin
182
Anton
182
 Sandy
183
E: METHODS OF SOLUTION 184
 1. Arithmagon
184
Specific solutions to the puzzle
184
The constraints method
184
Systems of equations
185
The method of false position
185
 General solutions
186
The usual formula 186
Stacey and Kerry’s method
186
Colin and Anton’s method
187
Eleanor’s method
187
 General problems
188
2. Fibonacci 
188
Properties of every nthFibonacci number
189
Generalizations of the Fibonacci sequence
189


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