Table Of ContentDesigning usable electronic text
Dedication
To err is human, to forgive design
This book is dedicated to my professional colleagues, past and present at
the HUSAT Research Institute, Loughborough University of Technology,
England.
Designing usable electronic text
Ergonomic aspects of human
information usage
Andrew Dillon
Indiana University
USA
UK Taylor & Francis Ltd, 4 John St., London WC1N 2ET
USA Taylor & Francis Inc., 1900 Frost Road, Suite 101, Bristol, PA
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This edition published in the Taylor & Francis e-Library, 2003.
Copyright © Taylor & Francis Ltd 1994
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ISBN 0-203-48173-9 Master e-book ISBN
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ISBN 0 7484 0112 1 (cloth)
ISBN 0 7484 0113 X (paper)
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Cover design by Hybert • Design&Type
Contents
Foreword.................................................................................................. viii
Acknowledgments ................................................................................... ix
1. The reading process and electronic text ................................................ 1
1.1 Introduction....................................................................... 1
1.2 The emergence of electronic text .................................... 1
1.3 The aims of the book ....................................................... 3
1.4 The scope of the book...................................................... 4
1.5 A note on methods ........................................................... 5
1.6 Outline of the book .......................................................... 8
2. Electronic documents as usable artefacts............................................... 11
2.1 The emergence of usability as a design issue................. 11
2.2 Usability as part of the product acceptability equation.... 13
2.3 Usability evaluation.......................................................... 15
2.4 The laboratory versus the field........................................ 17
2.5 What makes a technology more or less usable?............. 17
2.6 Towards effective user-centred design processes............ 18
2.7 Design and science........................................................... 23
2.8 Electronic documents as a technology?.......................... 26
3. So what do we know?............................................................................. 28
3.1 Introduction....................................................................... 28
3.2 The outline of the review................................................. 29
3.3 Observed differences: outcome and process measures .... 30
3.4 Outcome measures............................................................ 30
3.5 Process measures.............................................................. 38
3.6 Explaining the differences: a classification of issues..... 42
3.7 Physical sources of difference......................................... 43
3.8 Perceptual sources of difference...................................... 46
3.9 Cognitive sources of difference....................................... 51
3.10 General conclusion: so what do we know now? ............ 57
v
vi Contents
4. Describing the reading process at an appropriate level........................ 59
4.1 Introduction....................................................................... 59
4.2 The problem of theoretical description for human factors
work................................................................................... 63
4.3 Identifying an appropriate abstraction ............................ 65
4.4 Conclusions and the way forward................................... 69
5. Classifying information into types: the context of use......................... 72
5.1 Introduction....................................................................... 72
5.2 Reader-perceived distinctions between texts .................. 75
5.3 Readers, texts and tasks ................................................... 77
5.4 Results............................................................................... 77
5.5 Implications for electronic text design............................ 84
5.6 Conclusions and the way forward................................... 86
6. Capturing process data on reading......................................................... 87
6.1 Introduction....................................................................... 87
6.2 The range of texts to describe ......................................... 88
6.3 Presenting journals and manuals electronically: a brief
history................................................................................ 88
6.4 Describing text usage....................................................... 90
6.5 Basic investigative method............................................... 93
6.6 Describing text usage according to why, what and how
attributes............................................................................ 93
6.7 Design implications.......................................................... 101
6.8 General conclusions and the way forward...................... 103
7. Information as a structured space........................................................... 105
7.1 Introduction....................................................................... 105
7.2 The concept of structure in documents........................... 106
7.3 Schema theory as an explanatory framework................. 110
7.4 Identifying structural forms in electronic document
design ................................................................................ 115
7.5 Examining structure experimentally................................ 115
7.6 General discussion............................................................ 118
7.7 Conclusions....................................................................... 120
8. A framework for the design of electronic texts..................................... 121
8.1 Theory versus empiricism: the strained role of human
factors in the design process............................................ 121
8.2 Frameworks and models: a clarification of terminology 123
8.3 The proposed framework ................................................. 123
8.4 Interactions between the elements................................... 128
8.5 Qualitative versus quantitative representations............... 131
8.6 The utility of the proposed framework ........................... 135
Contents vii
9. Assessing the frameworks in terms of validity and utility................... 137
9.1 Introduction .......................................................................... 137
9.2 The validity experiment....................................................... 140
9.3 Results................................................................................... 144
9.4 Evidence for the interactive elements from readers’
protocols ............................................................................... 147
9.5 The utility experiment.......................................................... 152
9.6 Results................................................................................... 156
9.7 Discussion............................................................................. 158
9.8 The validity and utility of the framework .......................... 161
10. Designing usable electronic text: conclusions and prospects............... 162
10.1 Introduction .......................................................................... 162
10.2 The framework as a description of the reading process.... 162
10.3 The framework as a guide to design................................... 168
10.4 Further research.................................................................... 170
10.5 Specifying the design process for hypertexts..................... 171
10.6 General conclusion............................................................... 172
10.7 The prospects for electronic text......................................... 173
References................................................................................................ 176
Appendix: Example protocol for reader ................................................ 187
Index......................................................................................................... 193
Foreword
From humble beginnings automating routine clerical tasks the computer
industry is now attempting more daunting challenges; to support and expand the
capabilities of human beings in more complex, innovative intellectual tasks. So
far the results have not been very encouraging. Rather than liberating our
creative capabilities, we often find that these empowerment tools are confining
and inhibiting. A major reason is that we have too narrow a view of the human
task that we are trying to support with our technology. If the undoubted power
of modern technology is to be effectively harnessed, we need richer accounts of
the sophisticated human skills we seek to empower.
Andy Dillon has sought a deeper understanding of the very sophisticated and
significant skill of reading. His studies quickly dispel any notion that we
laboriously read from the first page to the last. We can have many purposes
when we pick up a text and we vary our reading strategy accordingly. The
richness and subtlety of the reading skill that these studies reveal will give pause
to any developer contemplating the opportunities of electronic texts.
As human scientists we always feel more comfortable when we can conduct
our studies under controlled, experimental conditions. Andy shows the value of
experimental studies but he also uses a wide range of other techniques. Each of
them adds another valuable perspective to our understanding of reading. His
work is testament to the importance of studying a phenomenon in context as
well as in the laboratory.
These studies of reading were undertaken while Andy was a member of the
HUSAT Research Institute. His work is an eloquent statement of the values and
objectives of the Institute in seeking to ensure technological developments
match human requirements and characteristics. It is a pleasure to acknowledge
Andy’s contribution to the intellectual development of the Institute and to
commend this account of reading to everyone who would seek to understand it
and to support it with technology.
Ken Eason
HUSAT Research Institute
November 1993
viii
Acknowledgments
This book owes so much to my working experiences at the HUSAT Research
Institute of Loughborough University of Technology in England where I spent
many happy times between 1986 and 1993. HUSAT is a speial place as
demonstrated by the fact that it has maintained an existence as a self-funding
research and consultancy group since 1970 solely on the basis of the
researchers’ abilities in applying the methods and knowledge of the human
sciences to the design of advanced technology. Long before the current vogue
of marketing ‘user-friendliness’, HUSAT advocated usability and an
appreciation of the users’ and organizations’ perspective in developing
acceptable new technologies. More than this, HUSAT convinced the design
and manufacturing worlds to support its work. While the 1980s produced
many new research groups in this field, I know of no comparable institute
worldwide.
In particular mention must be made of my closest working partners during
these years, Dr Cliff McKnight, John Richardson, Dr Martin Maguire and
Marian Sweeney who have put up with more than most, as well as David Davies
and many others too numerous to mention. HUSAT also gave me a chance to
work with two people who epitomize for me all that is positive in this domain:
Prof. Brian Shackel and Prof. Ken Eason. More than either will probably ever
realize they have had an impact on my thinking and convinced me that the
concern for user-centredness in technological developments is an area worthy
of intellectual and professional pursuit.
Time to write this book was partly funded by a visiting position at the
Institute for the Study of Human Capabilities, Indiana University,
Bloomington, USA where I met and argued with numerous people. Particular
mention here must be made of Prof. Chuck Watson for developing my interest
in individual differences, Prof. Tom Duffy of the Instructional Systems
Technology Group and Prof. Tom Schwen’s hit squad in the Centre for Media
in Teaching.
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