Why designers can't understand their users
Verhoef, L.W.M.
Citation
Verhoef, L. W. M. (2007, September 19). Why designers can't understand their users.
Human Efficiency, Utrecht. Retrieved from https://hdl.handle.net/1887/12347
Version: Corrected Publisher’s Version
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Institutional Repository of the University of Leiden
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Why designers can’t
understand their users:
developing a systematic
approach using cognitive
psychology
Leonard Verhoef
Verhoef, Leonardus Wilhelmus Maria
Why designers can’t understand their users: developing a systematic approach using cognitive psychology
Thesis Leiden University. – With ref. – With summary in Dutch.
ISBN-10: 908099751X ISBN-13: 9789080997516
© 2007, Leonard W. M. Verhoef,
Parkstraat 19, 3581 PB Utrecht, The Netherlands +31 (0)30 231 44 97,
verhoef@humanefficiency.nl www.humanefficiency.nl
www.humanefficiency.nl/designers_understanding.htm Cover: Rens Holslag, Leonard Verhoef
Printed by Human Efficiency, Utrecht
Why designers can’t
understand their users:
developing a systematic
approach using cognitive
psychology
Proefschrift ter verkrijging van
de graad van Doctor aan de Universiteit Leiden, op gezag van Rector Magnificus prof.mr. P.F. van der Heijden,
volgens besluit van het College voor Promoties te verdedigen op woensdag 19 september 2007
klokke 13:45 uur door Leonard Verhoef
geboren te Utrecht in 1950
Promotiecommissie Promotor:
prof. dr. P. Hudson Referent:
Prof. dr. K.A. Brookhuis Overige leden:
Prof. dr. W.A. Wagenaar Prof. dr. A. Rip
Dr. J. Groenewegen
Netherlands Railways facilitated the experiments reported in this thesis.
Contents 1
Contents
Introduction 7 Part I The Problem:
how to apply fundamental experimental psychological knowledge
1 From psychology to practice 13 2 Maintaining a scientific approach in practice 15 3 Which approach to apply 17 3.1 Elementary approach 17
3.2 Holistic approach 17
3.3 Synthetic approach 20
Part II The Solution:
a synthesis of psychological and design con-
cepts
4. The 'man' component 25 5. The 'interface' component 28 5.1 Interface technology approach 28 5.1.1Practical and experimental problems 28 5.1.2Theoretical problems 31 5.2 Properties approach 32 5.2.1Properties of the element of an interface 33 5.2.2The value of properties of elements 35 5.2.3The field properties of an interface 38 5.2.4Which field properties of the interface 39 1The field property quantity 40 2The field property distance 40 3The field property structure 40 5.2.5‘Man’ and ‘Interface’ 41
6. The 'task' component 42 7. Testing the Solution 44 7.1 Theoretical evaluation 46 7.2 Empirical test using students 46
Why designers can’t understand their users 2
7.3 Practical test by comparing designs 47 7.4 How the synthetic model will be tested 48
Part III Experiments:
better designs with the Solution?
8. Visual size 53
8.1 What is visual size? 53
8.2 Why visual size? 54
8.3 Which sizes? 54
8.4 Experiment: the effect of size on visual search per- formance 56
8.4.1Introduction 56
8.4.2Method 61
8.4.3Results 62
8.4.4Discussion 63
8.5 Generalisation of knowledge 65 8.5.1Interface technology generalisation: numerical
code train ticket vending machines 65 8.5.2Interface technology generalisation: screen train
ticket vending machines 66 8.5.3Domain generalisation: lists in computer interfaces
67
8.6 Conclusion 68
9. Visual distance 71
9.1 What is distance 71
9.2 Distance in other function fields 72 9.3 What is visual distance? 73 9.4 Why the term visual distance 74 9.5 Which visual distances 76 9.6 Experiment 1: comparison ‘Out of order’ 78
9.6.1Introduction 78
9.6.2Method 80
9.6.3Results 82
9.6.4Discussion 82
9.7 Experiment 2: comparison ‘Insert this way’ 83
9.7.1Introduction 83
9.7.2Method 85
9.7.3Results 87
9.7.4Discussion 87
9.8 Generalization of knowledge 89
Contents 3 9.8.1Interface technology independence: the 360-
destinations vending machine 89 9.8.2Interface technology independence: the touch-
screen vending machine 90 9.8.3Domain independence: a coffee vending machine 93
9.9 Conclusion 94
10. Cognitive quantity 97 10.1What is cognitive quantity 97 10.2Why cognitive quantity 97 10.3Which cognitive quantities 98 10.4Experiment 1: observation of performance 99
10.4.1Introduction 99
10.4.2Method 100
10.4.3Results 101
10.4.4Discussion 101
10.5Experiment 2: the effect of cognitive quantity 102
10.5.1Introduction 102
10.5.2Method 103
1The indicator used 103 2 Condition little information; single indicator 104 3 Condition large amount of information; double in- dicator 106
4Scoring 107
10.5.3Results 107
10.5.4Discussion 108
10.6Generalization of knowledge 109 10.6.1Interface technology generalisation: button train
ticket vending machine 109 10.6.2Domain generalisation: the Windows/ Office
terminology 114
10.7Conclusion 115
11. Cognitive structure 117 11.1What is cognitive structure? 117 11.2Structure in other function fields 119 11.3Why cognitive structure? 122 11.3.1Structure and literature 122 11.3.2 Structure and design 123 11.4Which cognitive structures? 127 11.5Experiment 1: observation of knowledge of the
structure 130
11.5.1Introduction 130
11.5.2 Method 131
Why designers can’t understand their users 4
11.5.3 Results 133
11.5.4 Discussion 134
11.6Experiment 2: comparison of structures 135
11.6.1 Introduction 135
11.6.2 Method 141
11.6.3 Results 142
11.6.4 Discussion 144
11.7Generalisation of knowledge 146 11.7.1 Interface technology generalisation 1: train
indicator 147 11.7.2 Interface technology generalisation 2: timetable
books 148 11.7.3 Domain generalisation: computer program menus
150
11.8Conclusion 152
Part IV Testing the Solution:
is the Solution really better?
12. Testing the Solution, using literature 156
12.1Shneiderman 156
12.1.1 Testing the human component 156 12.1.2 Testing the system component 157 12.2A web-based usability handbook 157 12.3A foundation of knowledge 159
12.4Conclusion 159
13. Testing the Solution, using the Solution 161 13.1Is the human component nominal? 162 13.2Is the human component ordinal? 163 13.3Is the system component nominal? 163 13.4Is the system component ordinal? 165 13.5The structure of the system components 165
13.6Conclusion 167
14. Epilogue 168 14.1Conservative domain 170 14.2Why bother, use new technology 171 14.3The results and conclusions are obvious and not
new 172
14.4The truth 173
14.4.1 Finding the truth with fora 173 14.4.2 Finding the truth with experiments 174 14.4.3Finding the truth with history 174
Contents 5 14.4.4The truth found? 175
Annexes 177
Annex 1: Design indicator experiments 178
1.1 Subjects 178
1.2 Materials 179
1.3 Procedure 180
1.4 Search time 180
1.5 Errors 180
1.6 Delay 180
1.7 Passenger evaluation 181 Annex 2: Random list with destinations 182 Annex 3: Table of contents: Software psychology 184 Annex 4: Table of contents: Designing the user interface
190 Annex 5: Structure of: A web-based handbook 194 Annex 6: Table of contents: Encyclopaedia of Ergonomics
and Human Factors 195 References 197 Summary 215
Samenvatting 221
Curriculum Vitae 227
Why designers can’t understand their users 6
