Designing Inclusive Interactions: Inclusive Interactions Between People and Products in Their Contexts of Use

Designing Inclusive Interactions

P. Langdon • P. John Clarkson P. Robinson Editors

Designing Inclusive Interactions Inclusive Interactions Between People and Products in Their Contexts of Use

123

Dr. Patrick Martin Langdon Department of Engineering University of Cambridge Trumpington Street Cambridge CB2 1PZ, UK [email protected]

Prof. Peter John Clarkson Department of Engineering University of Cambridge Trumpington Street Cambridge CB2 1PZ, UK [email protected]

Dr. Peter Robinson Computer Laboratory University of Cambridge 15 JJ Thomson Avenue Cambridge CB3 0FD, UK [email protected]

ISBN 978-1-84996-165-3 e-ISBN 978-1-84996-166-0 DOI 10.1007/978-1-84996-166-0 Springer London Dordrecht Heidelberg New York British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Control Number: 2010921207 © Springer-Verlag London Limited 2010 1-Clic™ is a registered trademark of Owens-Illinois Inc., One Michael Owens Way, Perrysburg, OH 435512999, USA, www.o-i.com Atmel® is a registered trademark or trademark of Atmel Corporation or its subsidiaries, in the US and/or other countries. Baseline™ is a registered trademark of Fabrication Enterprises, Inc., Post Office Box 1500, White Plains, New York 10602, USA, www.fabricationenterprises.com Bluetooth™ is a trademark of the Bluetooth SIG Inc., Bellevue, Washington, USA, www.bluetooth.com CorelDRAW is a trademark or registered trademark of Corel Corporation and/or its subsidiaries in Canada, the United States and/or other countries. Marmitek™ is a trademark of Marmidenko B.V., www.marmitek.com Windows® and Windows® are registered trademarks of Microsoft Cooperation in the United States and other countries Shellpak™ is a trademark of MeadWestVaco, 501 South 5th Street, Richmond, VA 23219, USA, www.meadwestvaco.com SPSS™ is a trademark of SPSS Inc., 233 S. Wacker Drive, 11th Floor, Chicago, IL 60606, USA, www.spss.com Wii™ is a trademark of Nintendo, www.nintendo.co.uk Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers. The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore free for general use. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. Cover design: eStudioCalamar, Figueres/Berlin Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

Preface

This book contains the foremost papers from the Cambridge Workshop on Universal Access and Assistive Technology (CWUAAT) held at Fitzwilliam College, Cambridge, in March 2010. This is the fifth of a series of workshops stemming from Inclusive Design that are held every two years in alternation with the Royal College of Art’s INCLUDE conference. The workshop theme, Designing Inclusive Interactions, responds to the recent changes in the research landscapes in the fields of Human Computer Interaction, Computer Science, and Healthcare as a result of new technology and innovation. As is evidenced by the themes of previous CWUAAT conferences, such as “Designing Inclusive Futures” (2008), Inclusive Design already brings together many of these disciplines within a context of ageing and disability. This has led us directly to the focus of this workshop on “Inclusive interactions between people and products in their contexts of use”. In the context of demographic changes leading to a greater number of older people, the general field of inclusive design research strives to relate the capabilities of the population to the design of products by better characterising the user-product relationship. By 2020, almost half the adult population in the UK will be over 50, with the over 80s being the most rapidly growing sector. Around 22% of the UK population were estimated to be disabled in 2003. Inclusive populations are known to contain a greater variation in sensory, cognitive and physical user capabilities. As a result, interaction design for future generations of products will need to be inclusive. Research into accessibility for interface design has always represented an unconventional, multi-disciplinary arena, indicating the necessity to bring together a number of pragmatic disciplines, such as assistive technology, mechanical and electrical systems design, computer interface design, and medical and rehabilitation practice. It has moved from isolated activities in disparate fields, such as engineering, occupational therapy and computer science, to the more interdisciplinary perspective evident today in areas such as healthcare and inclusive design. As a result of this, there is now a need for the transfer of knowledge and techniques from inclusive design research into the HCI community; and secondly,

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Preface

there is also a requirement for research that can relate complex interactions with a product to inclusion. It is our view that combining the study of interaction with an inclusive approach to user-centred design will form a novel and useful interdisciplinary framework for investigating and improving today’s product designs. The papers that have been included were selected by reference to the peer assessments of an international panel of reviewers from many key disciplines such as computer science, assistive technology, engineering and product design. This panel and the chapters from the final contributors represent a sample of leading national and international research in the fields of inclusive design, universal access, and assistive and rehabilitative technology. As in 2006 and 2008, there have also been significant trans-disciplinary contributions from researchers in architecture and healthcare reflecting the need to understand the new developments in the wider social and economic context of inclusive and assistive technology design. This book is divided into five areas: I.

II. III. IV. V.

Understanding Users for Inclusive Design concerns research that addresses the nature of inclusive performance, such as the effect of environmental context on capability in interaction; Measuring Inclusion focuses on the quantification of impaired capability and tools and methods to measure inclusion; Inclusive Interaction looks at research that brings together interface design and theory with inclusive capability requirments; Assistive Technology is about the relationship of inclusive design to special purpose design and adaptations for specific impairments; Inclusion and Healthcare looks at healthcare research in areas that encroach into design for greater inclusion.

In the tradition of CWUAAT, we have solicited and accepted contributions over a wide range of topics, both within individual themes and also across the workshop’s scope. We anticipate that this will encourage inter-disciplinary research leading to better designs. It is expected that that this will benefit industry, government and end-users thereby effectively reducing exclusion and difficulty, in the workplace, at home and at leisure. As in previous years but with additional emphasis, we would like to thank all those authors, reviewers and administrators who have contributed to the CWUAAT 2010 International Workshop and to the preparation of this book. Many thanks are due also to the non-contributing members of the Programme Committee. Finally, thanks are particularly due to Mari Huhtala and Suzanne Williams, who both play a key role in bringing the resulting publication to fruition between final submission and the Workshop itself. We would also like to thank the staff at Fitzwilliam College. Pat Langdon, John Clarkson and Peter Robinson The CWUAAT Editorial Committee University of Cambridge March 2010

Contents

List of Contributors …………………………………………………………....xi

Part I Understanding Users for Inclusive Design 1.

The Effects of Hand Strength on Pointing Performance P. Biswas and P. Robinson …………………………………………….....3

2.

Harnessing Different Dimensions of Space: The Built Environment in Auti-biographies S. Baumers and A. Heylighen ..………………………………………....13

3.

Have I Just Pressed Something? The Effects of Everyday Cold Temperatures on Dexterity E. Elton, D. Dumolo and C. Nicolle .…………………………………....25

4.

Understanding the Co-occurrence of Ability Loss S.D. Waller, E.Y. Williams, P.M. Langdon and P.J. Clarkson …….....35

5.

Accessibility is in the Palm of Your Hand E.M. Rodriguez-Falcon and A. Yoxall ………………..……………...…45

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Part II Measuring Inclusion 6.

Quantifying Exclusion for Tasks Related to Product Interaction S.D. Waller, E.Y. Williams, P.M. Langdon and P.J. Clarkson …........57

7.

Investigating the Accessibility of State Government Web Sites in Maryland J. Lazar, P. Beavan, J. Brown, D. Coffey, B. Nolf, R. Poole, R. Turk, V. Waith, T. Wall, K. Weber and B. Wenger ….................….69

8.

Developing User Data Tools: Challenges and Opportunities F. Nickpour and H. Dong ………………………………………..…...….79

9.

User-pack interaction: Insights for Designing Inclusive Childresistant Packaging J. de la Fuente and L. Bix ………………………………………………..89

10. A Colour Contrast Assessment System: Design for People with Visual Impairment H. Dalke, G.J. Conduit, B.D. Conduit, R.M. Cooper, A. Corso and D.F. Wyatt ………………………………………………………...…..…101

Part III Inclusive Interaction 11. Evaluating the Cluster Scanning System P. Biswas and P. Robinson …………….……………...……….……...113 12. Facets of Prior Experience and Their Impact on Product Usability for Older Users J. Hurtienne, A-M. Horn and P.M. Langdon ……………..…..………123 13. Investigating Designers’ Cognitive Representations for Inclusive Interaction Between Products and Users A. Mieczakowski, P.M. Langdon and P.J. Clarkson ………....……...133 14. Prior Experience and Learning: Generational Effects upon Interaction C. Wilkinson, P.M. Langdon, and P.J. Clarkson …………….....……145

Contents

ix

Part IV Assistive Technology 15. Expressing Through Digital Photographs: An Assistive Tool for Persons with Aphasia A. Al Mahmud, Y. Limpens and J.B. Martens ……………...….……..157 16. An Investigation into Stroke Patients’ Utilisation of Feedback from Computer-based Technology J. Parker, G.A. Mountain and J. Hammerton ………..……….……...167 17. How to Make a Telephone Call When You Cannot Operate a Telephone T. Felzer, P. Beckerle and S. Rinderknecht ………………….....……177 18. Husband, Daughter, Son and Postman, Hot-water, Knife and Towel: Assistive strategies for Jar opening A.Yoxall, J. Langley, C. Musselwhite, E.M. Rodriguez-Falcon and J. Rowson……………………………………………………….………. 187 19. Email Usability for Blind Users B. Wentz, H. Hochheiser and J. Lazar ………………………….…….197

Part V Inclusion and Healthcare 20. The Involvement of Primary Schools in the Design of Healthcare Technology for Children M. Allsop, R. Holt, J. Gallagher, M. Levesley and B. Bhakta ………209 21. Gaming and Social Interactions in the Rehabilitation of Brain Injuries: A Pilot Study with the Nintendo Wii Console R.C.V. Loureiro, D. Valentine, B. Lamperd, C. Collin and W.S. Harwin …………………………………………………………......219 22. Promoting Behaviour Change in Long Term Conditions Using a Self-management Platform P.J. McCullagh, C.D. Nugent, H. Zheng, W.P. Burns, R.J. Davies, N.D. Black, P. Wright, M.S. Hawley, C. Eccleston, S.J. Mawson and G.A. Mountain .…………………………………………………..……....229 Index of Contributors …………………………………………………..…..239

List of Contributors

Allsop M.J., Institute of Engineering Systems and Design, School of Mechanical Engineering, University of Leeds, Leeds, UK Al Mahmud A., Department of Industrial Design, Eindhoven University of Technology (TU/e), Netherlands Baumers S., Department of Architecture, Urbanism and Planning, Katholieke Universiteit Leuven, Leuven, Belgium Beavan P., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Beckerle P., Institute for Mechatronic Systems in Mechanical Engineering, TU Darmstadt, Darmstadt, Germany Biswas P., Computer Laboratory, University of Cambridge, Cambridge, UK Bix L., School of Packaging, Michigan State University, MI, US Bhakta B., Academic Department of Rehabilitation Medicine, Faculty of Medicine and Health, University of Leeds, Leeds, UK Black N.D., Pro-vice Chancellor for Research and Innovation, University of Ulster, UK Brown J., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Burns W.P., School of Computing and Mathematics, University of Ulster, UK Clarkson P.J., Engineering Design Centre, Department of Engineering, University of Cambridge, Cambridge, UK Coffey D., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Collin C., Royal Berkshire NHS Foundation Trust, Reading, UK Conduit B.D., Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK

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List of Contributors

Conduit G.J., Department of Condensed Matter Physics, Weizmann Institute of Science, Ben Gurion University, Beer Sheva, Israel Cooper R.M., Selwyn College, Cambridge, UK Corso A., Design Research Centre, Faculty of Art, Design and Architecture, Kingston University, UK Dalke H., Design Research Centre, Faculty of Art, Design and Architecture, Kingston University, UK Davies R.J., School of Computing and Mathematics, University of Ulster, UK De la Fuente J., School of Packaging, Michigan State University, MI, US Dong H., Inclusive Design Research Group, School of Engineering and Design, Brunel University, West London, UK Dumolo D., Department of Human Sciences, Loughborough University, Loughborough, UK Eccleston C., Bath Pain Management Unit, University of Bath, UK Elton E., Ergonomics and Safety Research Institute, Loughborough University, Loughborough, UK Felzer T., Institute for Mechatronic Systems in Mechanical Engineering, TU Darmstadt, Darmstadt, Germany Gallagher J.F., Institute of Engineering Systems and Design, School of Mechanical Engineering, University of Leeds, Leeds, UK Hammerton J., Faculty of Health and Wellbeing, Sheffield Hallam University, Sheffield, UK Harwin W.S., School of Systems Engineering, University of Reading, Reading, UK Hawley M.S., Health Services Research, University of Sheffield, UK Heylighen A., Department of Architecture, Urbanism and Planning, Katholieke Universiteit Leuven, Leuven, Belgium Hochheiser, J., Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, PA, US Holt R.J., Institute of Engineering Systems and Design, School of Mechanical Engineering, University of Leeds, Leeds, UK Horn A-M., Department of Business and Economics, Freie University Berlin, Berlin, Germany Hurtienne J., Engineering Design Centre, Department of Engineering, University of Cambridge, Cambridge, UK Lamperd B., Royal Berkshire NHS Foundation Trust, Reading, UK Langdon P.M., Engineering Design Centre, Department of Engineering, University of Cambridge, Cambridge, UK Langley J., Art and Design Research Centre, Sheffield Hallam University, Sheffield, UK Lazar J., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Levesley M.C., Institute of Engineering Systems and Design, School of Mechanical Engineering, University of Leeds, Leeds, UK Limpens Y., Department of Industrial Design, Eindhoven University of Technology (TU/e), Netherlands

List of Contributors

xiii

Loureiro R.C.V., School of Systems Engineering, University of Reading, Reading, UK Martens J.B., Department of Industrial Design, Eindhoven University of Technology (TU/e), Netherlands Mawson S.J., Centre for Health and Social Care Research, Sheffield Hallam University, UK McCullagh P.J., School of Computing and Mathematics, University of Ulster, UK Mieczakowski A., Engineering Design Centre, Department of Engineering, University of Cambridge, Cambridge, UK Mountain G.A., School of Health and Related Research, University of Sheffield, Sheffield, UK Musslewhite C., Centre for Transport and Society, University of the West of England, Bristol, UK Nickpour F., Inclusive Design Research Group, School of Engineering and Design, Brunel University, West London, UK Nicolle C., Ergonomics and Safety Research Institute, Loughborough University, Loughborough, UK Nolf B., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Nugent C.D., School of Computing and Mathematics, University of Ulster, UK Parker J., Centre for Health and Social Care Research, Faculty of Health and Wellbeing, Sheffield Hallam University, Sheffield, UK Poole R., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Rinderknecht S., Institute for Mechatronic Systems in Mechanical Engineering, TU Darmstadt, Darmstadt, Germany Robinson P., Computer Laboratory, University of Cambridge, Cambridge, UK Rodriguez-Falcon E.M., Department of Mechanical Engineering, The University of Sheffield, Sheffield, UK Rowson J., Department of Mechanical Engineering, The University of Sheffield, Sheffield, UK Turk R., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Valentine D., Royal Berkshire NHS Foundation Trust, Reading, UK Waith V., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Wall T., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Waller S.D., Engineering Design Centre, Department of Engineering, Cambridge University, Cambridge, UK Weber K., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Wenger B., Department of Computer and Information Sciences, Universal Usability Laboratory, Towson University, US Wentz B., Department of Computer and Information Sciences, Center for Applied Information Technology and Universal Usability Laboratory, Towson University, Towson, MD, US

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List of Contributors

Wright P., Cultural, Communications and Computing Research Institute, Sheffield Hallam University, UK Wilkinson C., Engineering Design Centre, Department of Engineering, University of Cambridge, Cambridge, UK Williams E.Y., Engineering Design Centre, Department of Engineering, Cambridge University, Cambridge, UK Wyatt D.F., Engineering Design Centre, Department of Engineering, University of Cambridge, Cambridge, UK Yoxall A., Art and Design Research Centre, Sheffield Hallam University, Sheffield, UK Zheng H., School of Computing and Mathematics, University of Ulster, UK

Part I

Understanding Users for Inclusive Design

Chapter 1 The Effects of Hand Strength on Pointing Performance P. Biswas and P. Robinson

1.1 Introduction Pointing tasks form a significant part of human-computer interaction in graphical user interfaces. Fitts’ law (Fitts, 1954) and its variations (Mackenzie, 2003) are widely used to model pointing as a sequence of rapid aiming movements, especially for able-bodied users. Fitts’ Law predicts the movement time as a function of the width and distance to the target. This law is found to be very robust and works in many different situations (even in space and under water). However the application of Fitts’ Law for people with motor impairment is less clear. We have investigated also how the pointing performance of people with motor impairment varies from their able-bodied counterparts. In particular, we have studied how physical strength affects the pointing performance of people with and without motor impairment for different input devices. We have used this study to develop a simulator to help with the design and evaluation of assistive interfaces (Biswas and Robinson, 2008b). The simulator embodies both the internal state of a computer application and also the perceptual, cognitive and motor processes of its user. It takes a task definition and locations of different objects in an interface as input. It then predicts possible eye movements and cursor paths on the screen and uses these to predict task completion times. We hope this study will be helpful to understand and analyse the interaction patterns of people with motor impairment and design better assistive interfaces for them. It will also help in explaining motor action and developing better motor-behaviour models for motor impaired users. In this study, we have measured the physical strength of users by evaluating their hand strength in terms of flexibility and maximum exerted force. It has already been found that the active range of motion (ROM) of the wrist is significantly correlated with movement time in a Fitts’ Law task for children with spasticity (Smits-Engelsman et al., 2007). Hand evaluation devices are cheap, easy to operate and have good test-retest reliability (Mathiowetz et al., 1984). So these are reliable and useful tools for measuring physical strength making these results useful in practice. Our study consisted of the following three experiments:

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Biswas and Robinson

1. the first experiment involved pointing tasks using a mouse and was undertaken by both motor impaired and able-bodied participants; 2. the second experiment involved pointing tasks using single switch scanning techniques and was undertaken by both motor impaired and able-bodied participants; 3. the third experiment involved two dimensional Fitts’ Law pointing tasks using a mouse, and was undertaken only by able-bodied participants. The remainder of this paper presents the experiments in more detail.

1.2 Experiment One: Pointing Tasks 1.2.1 Procedure, Material and Participants Our study consisted of pointing tasks. A sample screenshot of the task is shown in Figure 1.1. We followed the description of the multiple tapping tasks in ISO 9241 part 9 (ISO, 2000). In this task the pointer initially located at the middle of the screen. The participants had to move it towards a target (one of the red dots, appearing a light grey in monochrome), and click on it. This process was repeated for all the targets. There were eight targets on the screen and each participant performed the test twice (except participant P2, who retired after completing the first test). The distances to the targets ranged from 200 to 600 pixels while target widths were randomly selected as an integer between 16 and 48 pixels.

Figure 1.1. Screenshot of the experiment for mouse interface

We used a standard optical Mouse and an Acer Aspire 1640 Laptop with a 15.5” monitor having 1280×800 pixel resolution. We also used the same seating arrangement (same table height and distance from table) for all participants. We measured the following six variables for hand strength evaluation. Each was measured three times and we took the average. We evaluated only the dominant hand (the hand participants used to operate the mouse). Photographs of the measurement technique can be found at reference (Kaplan, 2006). Grip strength measures how much force a person can generate by gripping by hand. We

The Effects of Hand Strength on Pointing Performance

5

measured it using a mechanical dynamometer. Tip pinch strength measures the maximum force generated by a person squeezing something between the tips of his thumb and index finger. We measured it using a mechanical dynamometer. The following ranges of motion are defined with respect to the standard anatomical position (Kaplan, 2006). Radial deviation is the motion that rotates the wrist away from the midline of the body when the person is standing in the standard anatomical position (Kaplan, 2006). When the hand is placed over a table with palm facing down, this motion rotates the hand about the wrist towards the thumb. We measured the maximum radial deviation using a goniometer. Ulnar deviation is the motion that rotates the wrist towards the midline of the body when the person is standing in the standard anatomical position. When the hand is placed over a table with palm facing down, this motion rotates the hand about the wrist towards the little finger. We measured it with the goniometer. Pronation is the rotation of the forearm so that the palm moves from a facing up position to a facing down position. We measured it using a wrist-inclinometer. Supination is the opposite of pronation, the rotation of the forearm so that the palm moves from a facing down position to a facing up position. We measured it with the wrist-inclinometer. We collected data from 10 motor impaired and six able-bodied participants (Table 1.1, next page). The motor impaired participants were recruited from a local centre, which works on treatment and rehabilitation of disabled people and they volunteered for the study. To generalise the study, we selected participants with both hypokinetic (e.g. restricted movement, participants P1, P3, P4 etc.) and hyperkinetic (e.g. uncontrolled movement/tremor, participants P5, P6 etc.) movement disorders (Flowers, 1976). All motor impaired participants used a computer at least once each week. Able-bodied participants were students of our university and expert computer users.

1.2.2 Results We found that the movement time significantly correlates (ρ = 0.57, p < 0.001) with the number of pauses. We defined a pause as an instance while the pointer does not move for more than 100 msec. We correlated the average number of pauses per pointing task with the hand strength metrics. Figure 1.2 shows the graphs of average number of pauses per pointing task with respect to the Grip Strength. We found that some users did not have any range of motion in their wrist, though they managed to move the mouse to perform the pointing tasks correctly. We also found that the natural logarithm of grip strength significantly correlates with the mean (ρ = -0.72, p < 0.001) and standard deviation (ρ = -0.53, p < 0.05) of the number of pauses per pointing task. We did not find any correlation between that movement time and the distance, width or Fitts’ Law index of difficulty (ID) (Fitts, 1954) of the targets for motor impaired users. This may be due to the presence of physical impairment and the number of pointing tasks (only 16) performed by the participants. We also did not find any significant correlations involving ranges of motion. More details about these results can be found in a separate paper (Biswas and Robinson, 2009).

6

Biswas and Robinson Table 1.1. List of participants Age

Gender

Impairment

C1 C2 C3 C4 C5

30 29 28 25 29

M M M M M

Able-bodied

C6

27

F

P1

30

M

P2

43

M

P3

25-45

F

P4

30

M

P5

62

M

P6

44

M

P7

46

F

P8

>45

F

Spina Bifida/ Hydrocephalus wheelchair user

P9

43

F

P10

>45

M

Did not mention disease restricted hand movement no tremor Cerebral Palsy from birth restricted hand movement no tremor.

Cerebral Palsy reduced manual dexterity wheel chair user Cerebral Palsy reduced manual dexterity also some tremor in hand wheel chair user One handed (dominant hand) the other hand is paralysed Dystonia cannot speak cannot move fingers wheelchair user Left side (non-dominant) paralysed after a stroke in 1973 also has tremor Cerebral attack significant tremor in whole upper body part fingers always remain folded Did not mention disease difficulty in gripping things no tremor

Number of Pauses vs. Grip Strength 18

Number of Pauses

16 14 12 10

Motor-impaired Able-bodied

8 6 4 2 0 0

10

20

30

40

50

60

70

Grip Strength (in Kg)

Figure 1.2. Average number of pauses per pointing task vs. grip strength

We divided the whole movement path into three phases (Biswas and Robinson, 2008b, 2009) and observed how the hand strength affects in the initial, main movement and homing phases. We found that grip strength significantly correlates with the average number of pauses near the source (ρ = -0.61, p < 0.01) and near the

The Effects of Hand Strength on Pointing Performance

7

target (ρ = -0.78, p < 0.001). We also found that the mean and standard deviation of the velocity of movement were significantly correlated with grip strength (Figure 1.3, ρ = 0.82, p < 0.001 for mean and ρ = 0.81, p < 0.001 for standard deviation). Velocity vs Grip Strength

Velocity (in pixel/msec)

0.4

Mean Velocity

0.35 0.3

Stddev Velocity

0.25 0.2

Linear (Stddev Velocity) Linear (Mean Velocity)

0.15 0.1 0.05 0 0

10

20

30

40

50

60

70

Grip Strength (in Kg)

Figure 1.3. Velocity of movement vs. grip strength

1.3 Experiment Two: Scanning Study Many physically challenged users interact with a computer through one or two switches with the help of a scanning mechanism. Scanning is the technique of successively highlighting items on a computer screen and pressing a switch when the desired item is highlighted. In this study we used two scanning systems. A block scanning system iteratively segments the screen into equally sized sub-areas. The user has to select a sub-area that contains the intended target. The segmentation process iterates until the sub-area contains a single target. A cluster scanning system iteratively divides the screen into several clusters of targets based on their locations. The user has to select the appropriate cluster that contains the intended target. The clustering process iterates until the cluster only contains a single target. Details of these scanning systems can be found in our previous paper (Biswas and Robinson, 2008a).

1.3.1 Procedure, Material and Participants In this experiment, the participants were instructed to press a set of buttons arranged on a screen (Figure 1.4) in a particular sequence. All of the buttons were coloured grey except the next target, which was red. After selecting the target its colour changed to grey and another target became red. The same task was repeated for both the scanning systems. We recorded the cursor trajectories, target height, width, and task completion time. For internal validity of the experiment, the scan delay was kept constant at two seconds for all motor impaired participants and at one second for the control group since the reaction times of motor impaired users

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Biswas and Robinson

were longer. These values were selected to exceed their maximum measured reaction time. All participants were trained adequately with the scanning systems before undertaking the experiment.

Figure 1.4. Screenshot of the experiment

We used a push button switch (The Super-Switch, 2007) and an Acer Aspire 1640 Laptop with a 15.5” monitor having 1280×800 pixel resolution. We used the same seating arrangement for all participants. We measured the same six variables for hand strength evaluation as in Experiment One. We collected data from eight motor impaired (all participants except P3 and P9 in Table 1.1) and eight able-bodied participants (five female, three male, average age 28.75). The motor impaired participants were recruited from a local centre and they volunteered for the study. All motor impaired participants used a computer at least once each week. Able-bodied participants were students of our university and expert computer users. None of the participants had used the scanning systems before.

1.3.2 Results We measured the following three variables to investigate the scanning systems: • • •

Number of missed clicks: We counted the number of times the participants wrongly pressed the switch. Idle count: The scanning systems periodically highlight the buttons. This variable measures the number of cycles when the participants did not provide any input, though they were expected to do so. Efficiency: The scanning systems require a minimum time to complete any task which depends on the particular scanning system and not on the performance of the user. We calculated the efficiency as the ratio OptimalTime . An efficiency of 100% indicates optimal performance, ActualTime

50% indicates taking twice the minimal time and 0% indicates failure to complete the task. Table 1.2 shows the correlation coefficients of these variables with the hand evaluation metrics. The only significant effect is a correlation between the number

The Effects of Hand Strength on Pointing Performance

9

of missed clicks in the cluster scanning system and grip strength; there was a similar, but weaker, effect in the block scanning system. It seems that hand strength does not affect performance of users with the scanning systems. An equal variance t-test did not find any significant difference between the performance of motor impaired and able-bodied users at the p < 0.05 level. We also failed to find any effect of target size (height and width) on the task completion time, which is not surprising as the scanning systems did not depend on target size. Table 1.2. Correlation coefficients for the scanning systems (* significant at p < 0.05) Cluster Scanning System

Correlations

Significance

Block Scanning System

Missed Click

Idle Count

Efficiency

Missed Click

Idle Count

Efficiency

GS

0.580*

-0.191

0.168

-0.429

-0.331

0.283

TPS

-0.374

-0.105

0.110

-0.271

-0.153

0.093

ROM Wrist

-0.414

-0.154

0.189

-0.127

-0.120

0.068

ROM Forearm

0.000

0.106

-0.079

-0.268

-0.225

0.076

GS

0.018

0.478

0.534

0.097

0.210

0.289

TPS

0.153

0.699

0.686

0.310

0.572

0.731

ROM Wrist

0.111

0.569

0.484

0.639

0.659

0.803

ROM Forearm

1.000

0.695

0.770

0.315

0.401

0.778

1.4 Experiment Three: Fitts’ Law Study After analysing the effect of hand strength of motor impaired users, we also investigated how hand strength affects performance of able-bodied users. It would help to compare and contrast the pointing patterns of motor impaired users from their able bodied counterpart.

1.4.1 Procedure, Material and Participants Fitts’ Law provides a robust and accurate model for rapid aiming movements of able-bodied users. So we conducted a 2-dimensional Fitts’ Law task. We used 26 different combinations of target amplitude (A, ranged from 30 to 700 pixels) and

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target width (W, ranged from 16 to 48 pixels). The resulting index of difficulty (ID) ranged from 2 to 5. Each participant performed 450 pointing tasks. We used a standard optical Mouse and an Acer Aspire 1640 Laptop with 15.5” monitor having 1280×800 pixel resolution. We also used the same seating arrangement for all participants. We measured the same six variables for hand strength evaluation as in Experiment One. We collected data from 14 able-bodied users (nine male, five female, and age range 22 to 50 with average age of 29.3). All participants were expert computer users.

1.4.2 Results The correlation coefficients between index of difficulty (ID) and movement time ranges from 0.73 to 0.95 with an average value of 0.85, which conforms to Fitts’ Law. We compared the hand evaluation metrics with the Fitts’ Law coefficients (a ID ⎛A ⎞ ). We and b where, MT = a + b log2 ⎜ W +1⎟ and Index of Performance (IP = MTAverage Average ⎝ ⎠ found that IP is significantly correlated with the grip strength and tip pinch strength (ρ = 0.57, p < 0.05 for grip strength, ρ = 0.72, p < 0.005 for tip pinch strength, Figures 1.5 and 6 respectively). The parameter b significantly correlates with tip pinch strength (ρ = 0.65, p < 0.01, Figure 1.7). We did not find any other significant correlation between IP, a, b and any other hand evaluation metrics.

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Figure 1.5. Index of performance vs. grip strength IP vs. Tip Pinch Strength

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Figure 1.6. Index of performance vs. tip pinch strength

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Figure 1.7. Parameter b vs. tip pinch strength

1.5 Discussion For able-bodied users, pointing performance is generally analysed in terms of Fitts’ Law. Fitts’ Law can be applied to rapid aiming movements in many different contexts, but a proper explanation of this law is still unclear. Crossman and Goodeve pioneered an early by limited mathematical explanation (Rosenbaum, 1991). Meyer and colleagues gave a generalised model of rapid aiming movements in which Fitts’ Law comes as a special case; however, alternative explanations are also available (e.g. the Mass Spring model) (Rosenbaum, 1991). However, Fitts’ Law does not account for the users’ physical abilities in predicting movement time. This seems reasonable for able-bodied users. Our analysis indicates that people having higher hand strength also have greater control in hand movement and can perform pointing faster. The positive correlation between the velocity of movement and grip strength also supports this claim. As motor impairment reduces the strength of a hand, motor impaired people lose control of hand movement. So the number of pauses near the source and target are significantly affected by grip strength. The logarithmic relation between grip strength and number of pauses indicates that there is a minimum amount of grip strength (about 20 kg) required to move the mouse without pausing more than twice. This threshold of 20 kg can be used to determine the type of input device suitable for a user, along with other factors like preference, expertise etc. Our analysis also showed that flexibility of motion (as measured by ROM of wrist or forearm) is not as important as strength of hand (as measured by grip strength). We found that hand strength affects pointing performance of able-bodied users, too. The positive correlation between index of performance and hand strength shows people with greater hand strength perform pointing faster. The correlation between the constant term b and tip pinch strength indicates a difference in movement patterns among people with different hand strengths. As the constant b indicates the effect of index of difficulty (ID) on the movement time, perhaps the movement pattern of people with higher hand strength mainly consists of an initial ballistic phase and does not have a long homing phase since time to complete the homing phase should depend more on the target characteristics. The opposite holds true for people with less hand strength.

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As the homing phase requires more control in hand-movement, the negative correlation between b and hand strength also indicates people having higher hand strength also have greater control in hand movement. We also failed to find any effect of hand strength on pointing performance while participants used the scanning systems. There are two possible explanations: • •

the switch used in scanning only requires a gentle push to operate and the hand strength of motor impaired users is sufficient to operate the switch; the scanning software does the navigation itself and the users need not move their hand to move the pointer.

This result with the scanning system also shows that an appropriate choice of assistive technology can make interaction independent of the physical strength of users.

1.6 References Biswas P, Robinson P (2008a) A new screen scanning system based on clustering screen objects. Journal of Assistive Technologies, 2(3): 24–31 Biswas P, Robinson P (2008b) Automatic evaluation of assistive interfaces. In: Proceedings of International Conference on Intelligent User Interfaces (IUI’08), Canary Islands, Spain Fitts PM (1954) The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology, 47: 381–391 Flowers KA (1976) Visual ‘closed-loop’ and ‘open-loop’ characteristics of voluntary movement in patients with parkinsonism and intention tremor. Brain, 99: 269–310 ISO (2000) Ergonomic requirements for office work with visual display terminals (VDTs): requirements for non-keyboard input devices. ISO 9241-9:2000. International Organization for Standardization, Geneva, Switzerland Kaplan RJ (2006) Physical medicine and rehabilitation review, 2nd edn. MacGraw Hill Mackenzie IS (2003) Motor behaviour models for human-computer interaction. In: Carroll JM (ed.) HCI models, theories, and frameworks: toward a multidisciplinary science. Morgan Kaufmann, San Francisco, CA, US Mathiowetz V, Weber K, Volland G, Kashman N (1984) Reliability and validity of hand strength evaluation. Journal of Hand Surgery, 9: 18–26 Rosenbaum DA (1991) Human motor control. Academic Press Inc., US Smits-Engelsman BCM, Rameckers EAA, Duysens J (2007) Children with congential spastic hemiplegia obey Fitts’ Law in a visually guided tapping task. Journal of Experimental Brain Research, 177(4): 431–439 The Super-Switch (2007) Available at: http://rjcooper.com/super-switch/index.html (Accessed on 19 November 2009)

Chapter 2 Harnessing Different Dimensions of Space: The Built Environment in Auti-biographies S. Baumers and A. Heylighen

2.1 Introduction An understanding of diversity is a key principle in the development of theories, tools and techniques of design for inclusion. In assembling new perspectives for inclusive design, we want to gain a more accurate insight into the diversity of people’s interaction with the designed environment. People with autism spectrum disorders, for example, due to their particular way of thinking, make sense of their surrounding world in a unique way. Starting from this notion, our research questions the relevance to them of the meaning attributed to the built environment in our society, by studying the interaction between the world of experience of people with autism and the design of the built environment. In this paper, we investigate the way people with autism talk about space and the importance they attach to their physical environment, as reflected in stories and autobiographies of people with autism themselves—in short, auti-biographies. By analysing their own descriptions, we try to gain more insight into an autistic way of thinking and acting in relation to the built environment.

2.2 Architectural Design and Autism In our society, designers have a significant impact on daily life. They commit themselves to certain ideas, which take shape in the artefacts they conceive. In architecture also, a design embodies the designers’ line of thought. The tangible space which is the materialisation of an architectural design, thus carries a whole ideological background. However, most people are only exposed to the concrete realisation of the architectural design, to the physical space surrounding them. Yet the way a person deals with this surrounding space and brings it into use does not only depend on the design of the physical space, infused with the ideas of the architect; it is to a large extent based on the personal interpretation this person

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attaches to the physical environment. Jakob von Uexküll (1934) elaborates how the same physical entity can play different roles in the worlds—die Umwelten—of different people. Following this line of thought, Marta Dischinger (2006) points out that in wayfinding different features may become landmarks, depending on the person’s interests, attention and perceptual possibilities. The specific disposition of each person can lead to a different interpretation of the environment, which can develop into another use of space. Whatever the disposition from which an architect designs a certain environment, eventually people interpret the built environment from a personal disposition and they use their surrounding space according to this particular interpretation. Starting from a wide diversity of people, this paper focuses on the interpretation of the environment and the use of space by people with Autism Spectrum Disorders (ASD), namely autism. Up till now, ASD is still diagnosed the basis of a characteristic behaviour, known as restricted and repetitive actions (Wing, 1997; Noens and van IJzendoorn, 2007). Nevertheless, the true essence of autism, underlying this distinctive behaviour, is thought to be situated in a characteristic difference in cognitive functioning (Noens and van Berckelaer-Onnes, 2004). Their specific ‘distinct’ way of perceiving and information processing causes people with ASD to make sense of their surrounding world in a unique way (de Roeck, 1997). Both the characteristic autistic behaviour and the particularly different way of sense-making of people with autism influence their spatial experience and their interaction with space. This is a central argument in exploring the confrontation between people with autism spectrum disorders and their built environment.

2.3 Through the Words of Themselves In trying to gain insight into the way people with ASD interpret their built environment and how they deal with space, we do not intend to analyse various scientific points of view or general considerations concerning the varied disorders of the autism spectrum; nor do we intend to investigate the behavioural ‘anomalies’, interpreted according to our own standards. Instead, our starting point is the way people with autism—themselves—think about their interaction with space, getting to the bottom of their own reflections on it. Since Susan Reynolds Whyte established that people with disabilities experience a general tension between their personal values—shaped by their personal experiences with disability—and the general values of larger society (Albrecht, 2003), we want to emphasise these personal values, drawing attention to their personal verbal accounts of the physical environment, and to question what they can impart to the general values. However, the way to gain access to the range of thought of people with autism is not obvious. Even though ASD includes a wide spectrum of disorders, showing a large range of capabilities, impairments in social interaction and communication are common characteristics of the autistic spectrum (Wing, 1997; Noens and van Berckelaer-Onnes, 2004). Nevertheless, a few people with autism find a way to pour out their thoughts and feelings by writing them down (Klonovsky, 1993). Some of them write in detail characteristic memories of their life (e.g. Gunilla

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Gerland, Daniel Tammet, Liane Holliday Willey), while others write their experiences and feelings in letters or diaries (e.g. Landschip (Landschip is a Dutch pseudonym, which can be translated as ‘Landship’), Birger Sellin, Dietmar Zöller) or they make their thoughts known in a leaflet (e.g. Lourens Bijlsma, Brad Rand, Jim Sinclair). The written reflections on their own life allow us to catch a glimpse of an autistic way of thinking. In this paper, those published autobiographies of people with autism—so-called auti-biographies—are used as a particular source to analyse the importance of the physical environment, the interpretation of this environment and the corresponding way of dealing with the built environment by people with autism. To start with, we will discuss the role of physical space in a number of auti-biographies, selected on the dual conditions of having been written (1) by people with autism and (2) about experiences of their own lives (Zöller, 1989; Sellin, 1993; Sinclair, 1993; van Dalen, 1994; Gerland, 1996; Rand, 1997; Willey, 1999; Bijlsma, 2000; Dumortier, 2002; Landschip and Modderman, 2004; Tammet, 2006). Analysing which meaning the authors ascribe to the built environment and how they behave in dealing with the surrounding space, we want to identify some characteristic elements in their reflections on the built environment.

2.4 Divergent Dimensions of Space 2.4.1 The Confidence in Physical Space ‘My consolation, my safe retreat in the world, was a brown armchair in one corner. I could just fit in behind it. With my face close to the back of it, I would stare into the upholstery so that I could see every tiny little bit of it. I became absorbed in the brown material, in its threads, in the minute holes between the threads. […] There was no energy to be found there, but there was rest, a way of keeping my mouth shut and holding on to a little of the energy that had otherwise been spent in trying to understand what was incomprehensible, how everything hung together.’ (Gerland, 1996)

The incomprehensibility of society is a frequently recurring theme in the studied autobiographies of people with autism. Contemporary society does not give the authors something to hold on to in understanding what this world is all about; their life stories reveal a continuous struggle for some grip on the world around them. In pursuit of a sense of certainty in this world, physical space is presented as a fixed and self-evident feature of the environment, as a physical entity that gives the sense of grip the authors are looking for. The physical space offers some grip, not only metaphorically, but also in the literal sense of the word: it is visible and tangible, one can perceive it. Physical space simply is, and gives a sense of certainty unlike the transient information and the concepts of life that are not directly perceptible, such as the inner self of human beings. In this respect, physical entities, either single objects or whole spaces, seem to inspire more confidence than people. “People were never safety points to me,” Gunilla Gerland (1996) writes, whereas objects could mean a reassurance, even in new and incalculable environments. Physical entities were the anchorages to the world, not

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other people. “I didn’t want to move house, most certainly not. Our house and garden were my security. The house was closer to me than people were.” However, Gerland mentions that, after all, from a physical point of view there is no essential difference between people and objects. Even human bodies, or empty faces, can be seen as physical entities in space. “Those [empty] faces were as lacking in content as furniture, and I thought that, just like furniture, they belonged in the rooms I saw them in.” Consequently, “sitting on the lap of a stranger, on the lap of an empty face, hadn’t been any more difficult than sitting on an armchair.” (Gerland, 1996) Other auti-biographers note the same essential similarity between people and objects. According to Brad Rand (1997): “When I’m not concentrating on people, they just look like shapes, like furniture and trees are shapes.” When it turns out that people are not only stage-property, that there is some inner self behind these other entities labelled as human beings, and that they too have a personal state of mind, it is no surprise that—being not on the same wavelength to understand these underlying characteristics—human beings cause an unsafe feeling. The meaningful world behind human beings generates some unpredictability and uncertainty. “Because of important reasons,” Birger Sellin (1993) writes, “I can find safety only in things. People are incalculable and distinct monsters.” Nonhuman predictable behaviour and iron regularity are thing-like traits that people can only try hard to simulate, and in this way, “people with autism are offered more grip, sometimes even literally so, by nonhumans than by humans” (Hendriks, 1998). The predictability and—perhaps indisputable—perceptibility of physical space inspire confidence in the authors of the selected auti-biographies. In the descriptions of Gunilla Gerland (1996), this confidence is even enhanced by the sense of confirmation of her inner feelings, evoked by the physical environment. She likes to wander round the residential area at night, lonely, and writes: “The world was quieter then, and it looked just as deserted as it felt. That tallied. [...] I liked it when things tallied, when there was both an internal and an external emptiness.” Gerland longs to relate the environment to her own senses. Furthermore, she explains her bent towards curved objects, her desire to touch them, triggered by the feeling of being so ‘straight’ inside. “It’s because my nervous system is rectilinear that I need to acquire a curve from outside. As if, when I really need an inner curve so as not to be so rigid, I have to find it somewhere outside myself.” In both cases, the surrounding space, either as a mirror or as a complement of her own inner sense, ensures her own feelings. The sense of certainty and confidence experienced in relation to the physical environment makes the auti-biographers seek comfort in tangible space rather than with other human beings. Gunilla Gerland (1996), faced with the threat of losing track of herself when the certainties in the social world were lost, slipped in behind the brown armchair, to find a safe retreat to be left in peace. And Liane H. Willey (1999), whenever she began to feel as though she would come unravelled, crawled into the symmetrical alcove under her bed, until she felt “as square and symmetrical as the alcove itself.” There she could always find herself. The tangible space is able to offer a place to come to one’s senses again, as a safety point amidst an incomprehensible society.

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2.4.2 The Hidden Logic of the Built Environment Even though in most stories of people with autism the physical space features as a source of certainty, there are more sides to the physical environment as utilised by society. Each of the considered auti-biographies reveals an unpredictable feeling with regard to the built environment, resulting from problems or ‘maladjusted’ behaviour experienced in dealing with it. A recurring problem concerns orientation and wayfinding. Several autibiographers describe situations in which they lose their spatial orientation, in outside environments as well as inside a building. J.G.T. van Dalen (1994), diagnosed to be slightly autistic, writes how easily he loses his way. Even in familiar environments, he has to think a lot to find the right way. Also Landschip describes how, although he practised the route between two points, he was still not able to find again this way under various circumstances, snow, a closed road, … (Landschip and Modderman, 2004). Dominique Dumortier (2002) mentions similar problems of orientation, even inside a building: after visiting a new apartment, she does not succeed in pointing out the right door to the exit. And Liane H. Willey (1999) and Daniel Tammet (2006) describe how they had to rely hopelessly on trial and error to find their way inside the school building. Gunilla Gerland (1996) nuances her wayfinding through the school. She is not only aware of her problems in finding the right way, but also of the differences between her and her classmates in using this building. This realisation causes some doubt about the certainty of the perceived environment: “There must be a sign of some sort on the doors,” she writes, “because the others didn’t hesitate over where they should go.” Her problems in dealing with the environment, but especially the realisation of a different use or interpretation of the environment compared to others, make Gerland question which innate abilities enable the others to retrieve this logic. Despite the certainty offered by the fixed physical space, the imagined organisation and assumed logic behind the tangible space causes confusion. In the same way, van Dalen (1994), impervious to a functional meaning of the built environment, is aware of his ‘dysfunctional’ reactions: “For example, I often experienced that I pushed the open-button to close the doors of the elevator and the other way around.” The button to close an elevator is usually indicated by two thick vertical lines, widely separated, which—from a structural point of view— represent an opened door. However, the meaning of this button is grasped from the two functional arrows between those lines, pointing to each other to represent the act of doors closing. The connotations and meanings attributed to the built environment in our society can lead to situations in which people with autism do not behave themselves according to the rules people without ASD inherently connect with it. Aware of their problems or—compared to others—’maladjusted’ behaviour in dealing with the built environment, most authors describe how they consciously try to develop strategies to get round these difficulties, and how they try to blur some differences towards outsiders. It is a search for tricks that allow them to function in an apparently spontaneous way (Dumortier, 2002), a search for skills as a compensation for the missing automatic pilot (Landschip and Modderman, 2004).

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In her attempt to harmonise her behaviour with the way of dealing with the environment she noticed with others, Gunilla Gerland (1996) developed theories that—in her opinion—were a useful aid in making sense of what was happening. Her theories became a truth that had an impact on how she tried to understand the world. “I desperately wanted to understand, and this led to theories: if everything looked in a certain way in the living-room—the sun shining in through the curtains, the ashtray on the table with a newspaper beside it—and if Kerstin then came back from school ... I thought that everything had to look exactly the same the next day, for her to come back from school. And in fact, it often did.” Strikingly enough, the auti-biographers, developing strategies to compensate for the experienced ignorance of a hidden logic behind the built environment, unconditionally connect their theories to the immediately perceptible space. Even the unpredictable side of the built environment is compensated for by reverting to the physical certainty of space.

2.5 Interpreting Their Words 2.5.1 A Conscious Perception of Space A rough overview of the role of the built environment in the auti-biographies under consideration reveals that the authors’ perception and interpretation of the built environment—and its divergent dimensions—is shaped by a recurring way of experiencing space: the continuous consciousness of physical space as a tangible entity. Presenting the physical environment as an anchorage of confidence in the world, as a safety point by contrast with human beings, this reliability seems to have its roots in the tangibility and perceptibility of space. The idea of perceiving humans as a physical entity, just like objects and spaces are physical entities, illustrates the essential logic behind the conscious way of perceiving their environment. The unsafe feeling caused by human beings is due to the unpredictable aspects of an ‘inner self hidden behind the physical, which cannot be perceived just like that. In the same way, the experienced unpredictable side of the built environment stems from what exceeds the directly perceptible. The way the physical environment is utilised in our society often requires a sense of more than what is really tangible. To succeed in orienting yourself and finding the right way, for example, it is necessary—even in familiar environments—to be able to imagine what is not immediately present, placing the real perception in a general conception of the environment. When viewing a certain door, Dominique Dumortier (2002) could not—just like that—imagine the space into which that door gave entrance. And walking through the city, she was not able to imagine where a certain street would end, even if she had walked it a few times before. According to van Dalen (1994), even the smallest change in his view point makes him perceive an almost totally new environment, and failing to relate one image to the other explains his problems in wayfinding. Merely building on directly

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perceptible aspects to interpret the built environment can apparently lead to problems in dealing with space or ‘maladjusted’ behaviour, compared to others. Moreover, attributing meaning to the built environment in our society, we begin with a range of non-perceivable, non-concrete information, which gives the tangible space an extra dimension. The built environment surpasses the physical space, and this is the area of the authors mentioned above experience their problems, which strongly suggest that their interpretation of the world is mainly based on immediate perceptions of the physical space. The auti-biographers’ consciousness of the tangible space is also present in their reaction to both the predictable and the unpredictable characteristics of the built environment. Developing strategies to compensate for the experienced problems in interaction with the built environment, the authors describe how they fall back on their experience of an inherent certainty of the existing tangible space. Landschip, for example, to control his movements and actions, explicitly refers to his position in relation to the surrounding space. He explains that the quality of coordination between his eyes and hands—a skill in which he excels at certain moments, whereas at other moments it leaves much to be desired—does not only depend on which activity he is doing, but often “it goes well as soon as I have ‘positioned’ myself in space.” It is the tangible environment that gives him the sense of certainty to position himself in space and for this reason, he writes, he feels more safe when he travels by bike than when he goes on foot: “That bicycle is literally and metaphorically something to hold on to, an anchor, a point of departure that makes me know, all the time, what is upside and what is downside of reality” (Landschip and Modderman, 2004). It is the act of touching the fixed, tangible environment that vouches for his sense of safety. Just like Landschip, Gunilla Gerland (1996), confused by an unexpected and piercing noise, looks for something to hold on to in the physical environment, so as not to lose her bearings. “The din made the ground under my feet disappear and I could neither see nor feel the world around me. Up and down were suddenly in the same place and I had no sense of where my feet were. [...] I had to feel something that stood still, something anchored, in a world that had suddenly become totally unpredictable.” The concrete perception of physical space—one more time—offers her an alternative way to make sense of what is happening.

2.5.2 An Own World of Experience In different spheres, the conscious experience of the physical environment, described in the auti-biographies, shows a unique mode of perception and consciousness. The authors are aware of what is, what is directly perceptible. They substantiate the experiences described in relation to the built environment by chronicling an ‘other’ way of thinking, which makes them perceive, interpret and experience the world around them in an ‘other’ way. To explain his problems in dealing with the built environment, van Dalen (1994) mentions that, according to him, the real causes have a perceptual nature. He discovered how he, as distinct from most other people, perceives the world in a structural way rather than a functional way, which involves another way of making sense of the environment.

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“Anyway, my perception functions in an unambigously different way,” Birger Sellin (1993) remarks. Landschip specifies his ‘other’ way of perceiving: “I do not think my senses are developed in a better or sharper way, I rather think that it is caused by what I’m doing with my sensory information” (Landschip and Modderman, 2004). Attempting to have complete cognitive control over the way he perceives the world around him and the way these perceptions are organised inside his head, he explicitly describes how he perceives the surrounding space by means of his body, and even how he consciously experiences his body. “Probably,” Landschip writes, “except for your senses, you have other means at your disposal to know who you are, and to define the boundaries between yourself and what is around you.” Nevertheless, he, himself, uses the perception of the boundaries of his body as a reference. In this context, he describes his fear of remaining seated on a chair for too long. It ends up blurring the difference between the chair and his body. “At a certain moment, the interface of the chair is as warm as my body temperature, and at that moment I have lost the boundary between me and that chair” (Landschip and Modderman, 2004). To support his attempts to harness the environment with his mind, Landschip is aware of the importance of a conscious perception of the world by using his body. Gunilla Gerland (1996) extends the importance of bodily experience with her attempts to mentally follow up everything she is doing. When she plans to visit new places, it always requires a precise preparation. But however much she tries to harness the unknown environment, preparing everything with her mind, there is always an unpredictable aspect: “All that remains, what I can’t prepare for, is the town’s tempo, what the air feels like, what the town sounds like—everything that gives it a colour inside me.” Thanks to a continuous focus on cognitively grasping everything, she is aware of the fact that it is only possible to experience that colour of a city by being physically present. The way the authors discussed consciously perceive the world and process information from the environment makes their view of the world unique. It does not only characterise their perception and interpretation of the built environment, but leaves its marks on their routine experience. “Autism is a way of being,” Jim Sinclair (1993) clarified. “It is pervasive; it colours every experience, every sensation, perception, thought, emotion, and encounter, every aspect of existence.” Autism, as a pervasive disorder, forcibly shapes the world of experience.

2.6 In a Wider Perspective A first analysis of the considered descriptions of the built environment by people with autism reveals a characteristic way of perceiving. Most authors of these autibiographies express how they experience their own perception of the world as different in comparison with other people. “I was only beginning to see how peculiar my world was,” relates Liane H. Willey (1999), “not wrong or embarrassing or unessential, just peculiar and different.” Due to their different way of perceiving, the authors look at the world in a different way, they interpret the world from this particular perspective and experience the world in a distinct way.

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Birger Sellin (1993) testifies: “In my world, I know my way well, but the reality is macabrely different.” To elaborate this ‘difference’ of worlds, Lourens Bijlsma (2000), convincingly describing his lack of overview of the environment, adds that an autistic person is not aware of it by himself: “it is the world as he got to know it.” The non-autistic environment clarifies for him that ‘reality’ contains more, that there are connections—assumed to be ‘real’ ones—that he is not able to perceive. It illustrates the power of society to disable: “Assuming that there is one way to be in a culture encourages the misunderstanding that those who are different from perceived norms are missing something, that it is their doing, that they are locked out for a reason, that they are in fact, in reality, disabled” (McDermott and Varenne, 1995). Due to the way certain skills are made to count in various social settings, the different world of experience of people with autism could be considered as a deprivation. However, the critique from a non-autistic world of experience could be reflected the other way around, turning the characteristics of autism into “something that everyone in the community could easily work with, and turn it into a strength” (McDermott and Varenne, 1995). “The AS community gives us much cause to celebrate,” states Liane H. Willey (1999). Jim Sinclair (1993) also explicitly transcends a sense of inferiority. Describing a child with autism as stranded in an alien world, he argues that this other world of people with autism invites our society, perhaps challenges our society, to look into their reality: “You’re going to have to give up the certainty that comes of being on your own familiar territory, of knowing you’re in charge, and let them teach you a little of [their] language, guide you a little way into [their] world.” It is an invitation that can be framed in the cultural disability model of Devlieger et al. (2003), suggesting that taking up a lens of disability, or an autistic point of view, enables us to ask questions about the dominant way of thinking of our society. Applying this stance to the analysis above—interpreting the built environment through the view of people with autism—an understanding of their descriptions can be a challenge to open our eyes towards a certain critique on the way we—so-called neurotypicals— think about the built environment. And what’s more, this unique point of view questions the way we assume our standards as normative in organising space in this society. Describing their world of experience, the authors uncover a direct and conscious way of experiencing the world, a plain view of the world that most of us are not aware of. In this way, the perspective of autism could prompt us to think about our own experience of space by throwing light on their particular experience, and challenges our way of thinking about the built environment. But the cultural model of disability goes further, taking advantage of the difference between worlds of experience by admitting an exchange between those different worlds. In Dubbelklik (Literally translated: ‘Double-click’) (Landschip and Modderman, 2004), a correspondence between a person with autism and a person without, this exchange between the different worlds of both authors is clearly represented. In the end, the two of them testify that, thanks to this dialogue, they did not only get to know each other, but also got to know themselves. The descriptions of Loes Modderman about the non-autistic world taught Landschip a great deal about his autism. Conversely, Landschip’s stories of his autism made Loes Modderman become acquainted with her non-autism. In this way, Modderman writes that, thanks

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to her contacts with Landschip, she—herself—realised more consciously the way she perceives and feels. Fascinated by the fact that ‘realities’ can be that different, she posits that this book is promising proof that “a bridge can be built between one world and the other, just like that, offering a valuable gift.” Looking for a bridge between two worlds of experience, this paper used the reading of auti-biographies as an approach to discover the world of experience of people with autism. “Writing is my first step out of the other world,” Birger Sellin (1993) explains. Studying their written stories with a focus on their interpretation of the built environment, this research maintained a specific approach to challenge the usual conception and design of space. However, starting from only a selection of auti-biographies, the scope of this research is limited. Insights can still be extended by analysing the work of some other major authors with autism (e.g. Temple Grandin). Moreover, considering only written stories of people with autism themselves—consciously putting into words their own actions and feelings—the understanding of their perspective is strictly limited to their own interpretation of experiences in interaction with the built environment. Looking ahead to further research, the analysis of these well-considered written reflections will be supplemented with an investigation of the real interaction of people with autism with the built environment, focusing on their performance of actions in space, and their spoken reflections on it. Despite the limitations of this research, the analysis of the built environment through the reflections of people with autism in their autobiographies seen allowed us to raise a corner of the veil covering the autistic perspective on the built environment. Using this particular approach, this study unveiled how an ‘other’ mental disposition can broaden the designers’ outlook on the built environment by accepting an exchange between both worlds of experience.

2.7 Acknowledgements This research is supported by the Research Foundation – Flanders (FWO), of which Stijn Baumers is a Ph.D. fellow. The research of Ann Heylighen is funded by the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement n° 201673. Special thanks should also go to Eva Boodman, for fine-tuning the English spelling and grammar in this paper.

2.8 References Albrecht G (2003) Disability values, representations and realities. In: Devlieger P, Rusch F, Pfeiffer D (eds.) Rethinking disability. The emergence of new definitions, concepts and communities. Garant, Antwerpen-Apeldoorn, The Netherlands Bijlsma L (2000) Wat autisme eigenlijk is, gezien door een autist. Engagement, 2000(1) De Roeck A (1997) Over autisme en cognitie: de andere informatieverwerking van mensen met autisme. Van Horen Zeggen, 37(4): 4–11

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Devlieger P, Rusch F, Pfeiffer D (2003) Rethinking disability as same and different! Towards a cultural model of disability. In: Devlieger P, Rusch F, Pfeiffer D (eds.) Rethinking disability. The emergence of new definitions, concepts and communities. Garant, Antwerpen-Apeldoorn, The Netherlands Dischinger M (2006) The non-careful sight. In: Devlieger P, Renders F, Froyen H, Wildiers K (eds.) Blindness and the multi-sensorial city. Garant, Antwerp-Apeldoorn, The Netherlands Dumortier D (2002) Van een andere planeet. Autisme van binnenuit. Houtekiet, Antwerpen/Amsterdam, The Netherlands Gerland G (1996) A real person. Life on the outside. Souvenir Press, London, UK Hendriks R (1998) Egg timers, human values, and the care of autistic youths. Science, Technology & Human Values, 23(4): 399–424 Klonovsky M (1993) Vorwort. In: Sellin B (ed.) Ich will kein Inmich mehr sein: Botschaften aus einem autistischen Kerker. Kiepenheuer & Witsch, Cologne, Germany Landschip, Modderman L (2004) Dubbelklik: autisme bevraagd en beschreven. EPO & VDA McDermott R, Varenne H (1995) Culture as disability. Anthropology & Education Quarterly, 26(3): 324–348 Noens I, van Berckelaer-Onnes I (2004) Making sense in a fragmentary world. Autism, 8(2): 197–218 Noens I, van IJzendoorn R (eds.) (2007) Autisme in orthopedagogisch perspectief. Boom Academic, Amsterdam, The Netherlands Rand B (1997) How to understand people who are different. Available at: www.autism-pdd.net/brad.htm, consulted 23/12/2008 (Accessed on 19 November 2009) Sinclair J (1993) Don’t mourn for us. Our Voice, 1(3) Sellin B (1993) Ik wil geen inmij meer zijn: Berichten uit een autistische kerker. Rotterdam: Thoth. Translation of: ‘Ich will kein Inmich mehr sein: Botschaften aus einem autistischen Kerker.’ Kiepenheuer & Witsch, Cologne, Germany Tammet D (2006) Born on a blue day. Hodder & Stoughton, London, UK van Dalen JGT (1994) Autisme van binnenuit bekeken. Kijken door licht-autistische ogen. Engagement, 3: 3–8 von Uexküll J (1934) Streifzuge durch die Umwelten von Tieren und Menschen. Julius Springer, Berlin, Germany Willey LH (1999) Pretending to be normal: living with Asperger’s Syndrome. Jessica Kingsley Publishers, London, UK Wing L (1997) The autistic spectrum. The Lancet, (350): 1761–66 Zöller D (1989) Als ik met je praten kon…: brieven en dagboeken van een autistisch kind. Utrecht: Uitgeverij Kosmos. Translation of: ‘Wenn ich mit euch reden könnte...’ Scherz, Bern, Switzerland

Chapter 3 Have I Just Pressed Something? The Effects of Everyday Cold Temperatures on Dexterity E. Elton, D.Dumolo and C. Nicolle

3.1 Introduction This paper details work on the effect of physical context of use on inclusive product interaction. Context of use refers to a set of circumstances which relate to the users, tasks, equipment/tools and environment (both Physical and Social) (ISO, 1998). In particular, the physical context of use refers to factors such as lighting levels, temperature, weather conditions, vibration, noise, the built environment, etc. Consideration of the context of use is an integral, although sometimes implicit, part of any product design process. When a mismatch between context and a product occurs, it is unlikely that the benefits of a product will be realised (Maguire, 2001). Recent evidence suggests context of use can have a multi-faceted impact on product use (e.g. increasing or decreasing user capability and/or increasing product demand) particularly with older adults who have significantly reduced capability due to their age (Elton et al., 2008). Specifically, it is the physical environment that significantly affects capability. The vast majority of product interactions make demands on the visual and dexterous (arm, hand and finger) capabilities of the user. Whilst other capabilities are also used, it is these that are most common. Several studies (Riley and Cochran, 1984; Havenith et al., 1995; Boyce, 2003) have reported the effect of the physical environment on vision and dexterity. However, such studies focus on the body’s physiological response to such conditions and generally investigate extremes, e.g. freezing temperatures. Whilst these studies indicate the extent to which the physical environment can affect capability, they have very little relevance to everyday scenarios where products are used. Previous research investigated the effect of everyday lighting levels on visual capabilities (Elton and Nicolle, 2009). This paper reports the findings from a pilot study that investigated the effect of an everyday winter temperature on dexterity and how this can affect product interaction.

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3.2 Dexterity Dexterity is referred to as a motor skill that is determined by a range of arm, hand and finger movements and the ability to manipulate with hand and fingers (Heus et al., 1995). Dexterity comprises both manual dexterity and fine finger dexterity. Fine finger dexterity refers to the ability to manipulate objects with the distal (fingertip) part of the hand. This involves precise movement of the fingers, e.g. writing, dialling a number, picking up a coin, fastening a button, etc. Manual dexterity involves less refined and less precise movements of the hand and fingers (Desrosiers et al., 1995). The object is usually larger and manipulation requires more gross movements, e.g. digging, opening a door, placing a saucepan on the hob, etc. Dexterity is extremely important in carrying out everyday product interactions and nearly all products in today’s marketplace require dexterity in one form or another. Functioning of the hands is determined by several physiological parameters that are described in Table 3.1. Table 3.1. Factors that influence dexterity (Heus et al., 1995) Component of dexterity

Description

Reaction time

The time between a stimulus being presented and the start of motor response

Sensibility (sensitivity)

The response of receptors in the skin to tactile, pressure, thermal and pain stimuli

Nerve conduction

The speed at which nerves conduct signals

Grip strength

The force that can be developed by the muscles of the upper and lower arm

Time to exhaustion

The time to when a decrease in force exerted by the muscles occurs

Mobility

The range of motion of the hands and fingers

3.3 Effects of the Cold on Dexterity When people are in cold environments the temperature of their body’s extremities reduces initially, caused by cold air coming into contact with the skin. When the skin cools, the blood flow to that area decreases, which results in less heat being dispersed to that part of the body (Edwards and Burton, 1959). This then lowers the temperature of the skin further. Cold also decreases the nerve conduction velocity (i.e. the speed the nerve sends a message from the brain to the muscles that control the hand). Furthermore, it causes the synovial fluid which lubricates the joints to become more viscous, so that movements are slower and require greater muscle power. In summary, dexterity (both manual and fine finger) is significantly

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reduced due to physiological effects of the cold on the human body (Heus et al., 1995). However, little is known about the extent to which typical everyday cold temperatures affect the functioning of the human hand and what effect this can have on a user’s capability to interact with a product. Is it just extreme temperatures that cause these physiological changes to occur, thus reducing dexterity, or could being outside for 20 minutes on a winter’s day have a significant effect?

3.4 Aims and Objectives The overall aim of this research is to produce a capability dataset that can be used by designers to produce products that are inclusive in the contexts in which they will be used. The specific objectives of this pilot study are to: • • • •

obtain an indication of which forms of dexterity are affected by the cold (approximately 5°C) and to what extent; determine the likely effect on product interaction; identify which tests are good predictors of product interaction capability; identify appropriate dexterity tests for a larger scale study.

3.5 Methods 3.5.1 Dexterity Tests Objective measures were used to assess dexterity as they have the advantage of providing direct measures of human response (Parsons, 2005). Manual and fine finger dexterity were measured using a combination of empirical tests and representative real world tasks. The aim of the pilot study was to identify from these tests which form(s) of dexterity are affected by the cold. The empirical tests chosen are detailed in Table 3.2 and the representative real world tasks chosen are detailed in Table 3.3.

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Elton, Dumolo and Nicolle Table 3.2. Empirical dexterity tests used in experiment

Test

Description

Purdue pegboard

A test of fine finger dexterity. The assessment involves a series of four subtests which involve placing as many pins as possible into a pegboard with the right hand, then the left hand and then both hands – each in a 30 second period. The fourth subtest is an assembly task using pins, collars and washers – this was not used in this experiment.

Power grip strength

Maximal grip strength (kg) a person can exert with their hand (measured by squeezing together the middle joints of all four fingers and the palm). Just the dominant hand was measured by following the standard protocol as provided with the dynamometer (Takei Scientific Instruments - T.K.K.5401 Grip D [Digital Grip Dynamometer]). The test was repeated three times and mean averaged.

Pinch grip strength

Maximal force that can be exerted between the index finger and thumb pulps. Just the dominant hand was measured in a standardised posture. The maximum force was measured in kg and was repeated three times then mean averaged. Equipment used was the Baseline Hydraulic Pinch Gauge.

Table 3.3. Representive real world tasks used in experiment Real world task

Description

The Moberg pickup test

A real world timed test that uses a combination of pinch grip and fine finger dexterity. The test requires participants to pick up a selection of 12 real world objects from a table and place them in a container as quickly as possible. The test was modified to use a selection of representative everyday products, including a mobile phone SIM card, paperclip, safety pin, AA battery, PDA stylus, match, UK 1p, UK 2p, credit card, key, bolt and wing nut. The test was repeated a second time and then mean averaged.

Using a mobile phone

The task requires fine finger dexterity. The time taken to enter an eleven digit number, in the style of a UK landline telephone number, into a mobile phone (NOKIA 3210e) was recorded.

Using gardening secateurs

The task requires the exertion of a power grip. Participants were asked to cut through increasing thicknesses of wooden dowel (3, 5, 6, 9, 10 and 12 mm diameters) using a pair of garden secateurs (B&Q Deluxe Branch and Thicker Stem Secateurs). The maximum thickness of dowel that they could cut through was recorded.

The rationale for selecting these particular dexterity measures will be detailed in another paper that is currently in preparation.

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3.5.2 Cold Temperatures The coldest outdoor temperatures in the UK are experienced through the winter months (December, January and February). Mean temperature across the country usually varies between -4°C to +8°C; however on average, mean temperatures lie around the 4–5°C mark (Met Office, 2009). Also, 5°C is the temperature threshold used by the Met Office to issue a cold weather warning (Goodwin, personal communication, 2009). Based on these national statistics and temperature thresholds, 5°C was the chosen temperature to represent cold environmental conditions.

3.5.3 Procedure A climatic chamber was used to regulate the desired temperature of 5°C. This had the advantage of ensuring consistency in testing conditions and elimination of experimental noise. Thermo-neutral testing (an environment that keeps the body at an optimum point) was conducted within a room adjacent to the climatic chamber which was regulated between 19°C–24°C. In order to replicate real world scenarios as closely as possible, each participant was asked to bring their own winter clothes (suitable for temperatures of 5°C) to wear in the climatic chamber. The only item of winter clothing they did not wear was gloves as the experiment was concerned with the effect of the cold on the hand/dexterity. Gloves are another variable that are known to influence dexterity. In a study conducted by Havenith and Vrijkotte (1993), it was found that wearing gloves decreased fine finger dexterity by up to 70% and hand dexterity by up to 40% in comparison to ungloved hands. Currently, there is no data that simultaneously details the effects of the cold and gloves on dexterity. However, in relation to this study, measuring the effects of the cold and gloves in one experiment is not practical, i.e. participants would have to spend prolonged time in the cold and would have to conduct double the number of tests which could easily result in fatigue, discomfort and significantly increased blood pressure. When in the climatic chamber participants were asked to sit for 20 minutes, prior to undertaking the battery of dexterity tests, in order to let their hands cool. In the thermo-neutral environment participants dressed in their ‘normal’ clothing for the time of year (summer 2009). A repeated measures design was chosen to provide the best comparison between the two types of environments. The order of experiencing the two environments and the dexterity tests was varied systematically using a balanced Latin square. This counter balancing of the conditions and tests mitigated against any order or carry over effects.

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3.5.4 Sample Since there is a lack of specific information on the prevalence of disorders affecting dexterity in the UK, it was not possible to recruit a random proportionate sample. An initial purposive sampling strategy to recruit a highly variant sample of users with mixed dexterity abilities was therefore adopted. A total of 14 participants (six male and eigth female), aged between 65 and 75 years (mean age=69.57, SD=3.756) completed the pilot study. A minimum age criterion for the sample was set at 65 years old as significant reductions in hand functions are seen after this age (Shiffman, 1992). It is these users who are already working to the limits of their ability; therefore any reduction in capability due to context would result in their being excluded. A dataset that details this reduction and variation in capability will allow for the design of mainstream products that are accessible to, and usable by, as many people as reasonably possible, without the need for special adaptation or specialised design (Clarkson et al., 2007).

3.5.5 Ethical Consideration Ethical clearance for the study was obtained from Loughborough University’s Ethical Advisory Committee. All participants answered a health screening questionnaire to ensure they had no conditions that could be adversely affected by the cold. They received a participant information pack that contained full details of the study prior to their arrival. During the study blood pressure and finger skin temperature were monitored to ensure they did not exceed safe levels based on expert and medical advice.

3.6 Results The results in this section detail the findings from the pilot study. All participants completed the battery of tests in both thermo-neutral (mean temperature=21.5°C, SD=0.75) and cold (mean temperature=5.7°C, SD=1.25) environments. Mean finger skin temperature in the warm was 30°C, and in the cold mean finger skin temperature reduced to 19°C. Outliers were removed and the data was tested for normality. Data for nearly all tests was normally distributed (parametric) apart from the Secateurs test, in both warm and cold conditions. Thus, median values and non parametric tests have been used to analyse the results for the Secateur data sets. The average performance for all dexterity tests in both the thermo-neutral and cold environments is detailed in Table 3.4.

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Table 3.4. Average dexterous performance in thermo-neutral and cold environments

Dexterity test

Thermoneutral average (SD)

Cold average (SD)

Difference in performance (%)

Purdue pegboard (R+L+Both = no. pins)

Mean = 35.50 (SD = 1.46)

Mean = 33.14 (SD = 1.02)

-7%

Power grip strength (kg)

Mean = 29.7 (SD = 11.29)

Mean = 28.87 (SD = 11.14)

-3%

Pinch grip strength (kg)

Mean = 5.75 (SD = 1.64)

Mean = 5.52 (SD = 1.53)

-4%

Moberg pickup test (sec)

Mean = 13.79 (SD = 2.21)

Mean = 15.74 (SD = 4.84)

14%

Mobile phone (sec)

Mean = 13.35 (SD = 4.28)

Mean = 14.20 (SD = 3.60)

6%

Median = 5 (IQR = 5)

Median = 5 (IQR = 5)

0%

Secateurs (max. diameter of dowel cut = mm)

A reduction in mean dexterity was observed on the Purdue pegboard (7% reduction), Moberg pick-up test (14% reduction) and the mobile phone task (6% reduction) when in the cold environment. A slight reduction was observed with grip strength performance (power 3% and pinch grip 4%) when in the cold environment. However, mean performance on the real world grip strength test using the Secateurs did not appear to be affected by the cold. Paired t-tests were used, on the normally distributed data, to determine whether there was a significant difference in performance between the two environments. The results from this analysis are detailed in Table 3.5. Table 3.5. Paired t-test results between the thermo-neutral and cold environment Dexterity test

Mean difference (SD)

Sig. (2-tailed) p