Designing Affordances on Embedded Interfaces

106 Pages·2015·4.08 MB·English

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Master's Theses Master's Theses and Graduate Research
Summer 2013
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Gabriela Madalina Istan
San Jose State University
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Istan, Gabriela Madalina, "Designing Affordances on Embedded Interfaces" (2013). Master's Theses.
4344.
DOI: https://doi.org/10.31979/etd.s4rj-ac9w
https://scholarworks.sjsu.edu/etd_theses/4344
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DESIGNING AFFORDANCES ON EMBEDDED INTERFACES

A Thesis
Presented to
The Faculty of Human Factors and Ergonomics Program
San José State University

In Partial Fulfillment
of the Requirements for the Degree
Master of Science

By
Gabriela M. Istan
August 2013
© 2013
Gabriela M. Istan
ALL RIGHTS RESERVED
The Designated Thesis Committee Approves the Thesis Titled

DESIGNING AFFORDANCES ON EMBEDDED INTERFACES
by
Gabriela M. Istan

APPROVED FOR THE PROGRAM OF HUMAN FACTORS AND ERGONOMICS
San José State University
August 2013
Dr. Sean Laraway, Department of Psychology
Dr. Emily H. Wughalter, Department of Kinesiology
Dr. Kevin Jordan, Department of Psychology
ABSTRACT
DESIGNING AFFORDANCES FOR EMBEDDED INTERFACES
by Gabriela M. Istan
The purpose of this study was to examine the effects of a user interface on users’
performance during an online shopping checkout task. Two interfaces were developed
using the principles of Rasmussen’s SRK model: a high-affordance and a
low-affordance interface. Seventy undergraduate and graduate students performed a
simulated online shopping task with the two interfaces. It was hypothesized that the
high-affordance interface would require less time and fewer clicks to conduct the
shopping task when compared to a low-affordance interface. In addition, it was predicted
that participants would prefer the high-affordance interface. The findings revealed
participants spent more time on the task using the high-affordance interface, but the
difference was not statistically significant. Participants made significantly fewer clicks
using the high-affordance interface than they did using the low-affordance interface.
Compared to the low-affordance interface, a significantly higher percentage of users
reported that they would prefer the high-affordance interface. This is one of the first
studies to examine the application of the SRK model to the design of consumer
interfaces. Based on these results, the SRK model may be considered another conceptual
tool to make interfaces easier to use and consumer experiences more satisfying and
enjoyable.
ACKNOWLEDGEMENTS
I would like to express my deepest appreciation to all those who provided me with the
support for completing this thesis. It is with immense gratitude that I acknowledge the
support and help of my thesis advisor, Dr. Sean Laraway. Thank you for your guidance,
good advice, and encouragement throughout planning, running, and writing the thesis. In
addition, I would also like to thank Dr. Emily H. Wughalter for her enthusiasm and
believing in me when no one else did. Thank you for your support and for teaching me
about research. My thanks also go to Dr. Kevin Jordan whose contributions and
suggestions aided with the coordination of the study. Finally, I would like to thank the
most important people in my life, my husband, Marian, and my parents for their
unconditional support. Marian, your love was a pillar of strength that helped me
overcome obstacles during this long road. Thank you for being a great inspiration for
me, teaching me that I should never surrender and supporting me to transform my dreams
into reality!

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TABLE OF CONTENTS
LIST OF FIGURES ........................................................................................................... ix
LIST OF TABLES .............................................................................................................. x
INTRODUCTION .............................................................................................................. 1
The Concept of affordance...................................................................................... 2
Perspectives on affordances .................................................................................... 3
Perceptual view ........................................................................................... 3
Cognitivist view of affordances in HCI ...................................................... 4
The exploratory nature of affordances ........................................................ 5
Hierarchical nature of affordances .............................................................. 6
Application of Gibson’s affordances in designing interfaces ................................. 8
An activity model of affordances ............................................................................ 9
The deep structure of affordances – the SRK model ............................................ 11
Abstraction hierarchy (I) ........................................................................... 12
Skills-Rules-Knowledge model (II) .......................................................... 13
Perceptual affordances in Human-Machine Interaction ....................................... 18
Expert affordances come with practice ................................................................. 18
Implications for interface design .......................................................................... 19
“Making visible the invisible” (Rasmussen, 1989)................................... 20
Concepts beyond affordances ............................................................................... 22
Simple and complex affordances .............................................................. 23
Learning affordances ................................................................................ 23
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Summary ............................................................................................................... 25
METHOD ......................................................................................................................... 29
Participants ............................................................................................................ 29
Setting and Apparatus ........................................................................................... 30
Materials ............................................................................................................... 31
Prototyping tool ........................................................................................ 31
Software tool ............................................................................................. 31
Procedures and Study Design ............................................................................... 32
Response Measures and Data Analysis..................................................... 34
RESULTS ......................................................................................................................... 36
Final questionnaire summary ................................................................................ 38
Post-hoc Analyses ................................................................................................. 41
DISCUSSION ................................................................................................................... 43
Conclusion ............................................................................................................ 51
REFERENCES ................................................................................................................. 53
APPENDICES
A. Human Subjects Institutional Review Board Approval ................................... 59
B. Demographic questionnaire.............................................................................. 60
C. High-affordance interface (HAI) or Interface X .............................................. 61
D. Low-affordance interface (LAI) or Interface Y ............................................... 72
E. Agreement to Participate in Research .............................................................. 84
F. The Instructions window .................................................................................. 85
vii
G. Post-task questionnaire (Interface X) ............................................................... 86
H. Post-task questionnaire (Interface Y) ............................................................... 87
I. Preference task screen ....................................................................................... 88
J. Preference survey .............................................................................................. 89
K. Summary of participants’ free responses ......................................................... 90

viii
LIST OF FIGURES

FIGURE 1. Participant online shopping frequency. ......................................................... 30

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