Designing for Humans Nature aside, the world in which we live should be designed for us, from everyday products like scissors and chairs to complex systems in avionics, medicine and nuclear power applications. Now more than ever, technological advances continue to increase the range and complexity of tasks that people have to perform. As a discipline, human factors psychology (ergonomics) therefore has an increasingly important role to play in ensuring that the human user’s physical characteristics, cognitive abilities and social needs are taken into account in the development, implementation and operation of products and systems. In this book, Jan Noyes provides a comprehensive and up-to-date overview of human-machine interaction and the design of environments at work. Focusing on topics relevant to user-centred design, she includes coverage of the capabilities and limitations of humans, human-machine interactions, work environments, and organisational issues. Health and safety issues underpin a large amount of work on the human factors of design, and these are addressed fully in this book. Each chapter includes case studies that demonstrate the real-world relevance of the points being made and concludes with a list of key points. Although aimed primarily at advanced undergraduates, postgraduates and researchers in organisational and occupational psychology, this book will also be of relevance to students on engineering, computing and applied psychology/human factors programmes. Jan Noyes is currently Graduate Dean of Science at the University of Bristol. Her research and teaching interests are in the area of human factors psychology, and more specifically, the design of interfaces for advanced and emerging technologies such as automatic speech recognition, pen-based products and high level warning systems. In 1999 she was awarded the prestigious Otto Edholm medal for her contributions to applied research in ergonomics. She is the co-editor (with Chris Baber) of Interactive speech technology: Human factors issues in the application of speech input/output to computers, published by Taylor & Francis in 1993. Psychology at Work Series Editor: Peter Robinson Professor of Social Psychology, University of Bristol The Psychology at Work series provides comprehensive coverage of the central issues and debates in work and occupational psychology today. Its aim is to take specific areas or problems within the world of commerce, industry and public service, and establish a dialogue between their practical concerns and the academic theory and research of work and organisational psychologists. It is hoped that the series will provide a resource that generates debate and facilitates the process by which policy and practice become informed by (and inform) critically evaluated evidence-based research. The comprehensive text by Christine Doyle; Psychology in Organisations: An Introduction, covers the central areas of the subject. Further texts cover options found on advanced courses in work and organisational psychology or examine contemporary and controversial topics within the field. The series will be of use to undergraduate and postgraduate students on work and occupational psychology courses, and will be particularly suitable for the British Psychological Society specification syllabus of accredited MSc courses in occupational psychology. It will also be of interest to those professionals in business and management eager to find out more about how work and organisational psychology can inform and improve the working environment. Other forthcoming titles in this series: Psychology in Organisations: An Introduction Christine Doyle The Psychological Contract at Work Jackie Dyer and Nicky Hayes The Psychology of Health and Safety at Work Robert Parkinson, Paul Lyons and Andrew Tattersall Personal Development and Employment David Williams and Judi Irving Designing for Humans Jan Noyes First published 2001 by Psychology Press Ltd 27 Church Road, Hove, East Sussex, BN3 2FA Simultaneously published in the USA and Canada by Taylor & Francis Inc, 29 West 35th Street, New York, NY 10001 This edition published in the Taylor & Francis e-Library, 2003. Psychology Press is part of the Taylor & Francis Group © 2001 Jan Noyes http://www.psypress.co.uk All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data Noyes, Janet M. Designing for humans/Jan Noyes. p. cm.—(Psychology at work) Includes bibliographical references and index. ISBN: 0-415-22721-6—ISBN: 0-415-22722-4 (pbk) 1. Human engineering. 2. Human-computer interaction. 3. Work environment. I. Title. II. Series. TA166 .N63 2001 620.8'2–dc21 2001019886 ISBN 0-203-46557-1 Master e-book ISBN ISBN 0-203-77381-0 (Adobe eReader Format) ISBN: 0-415-22721-6 (hbk) ISBN: 0-415-22722-4 (pbk) Cover design by Jim Wilkie For Emily Ceri The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends upon the unreasonable man. George Bernard Shaw, 1903, Man and Superman ‘Maxims for Revolutionists: Moderation’ Ergonomists must be ‘unreasonable’ in the sense that they will strive vigorously and increasingly to support a meaningful and productive relationship between technology and mankind, that technology and its products might be used for the ennoblement and fulfilment of mankind and not for its disenfranchisement and, finally, that instead of attempting to be the master of nature with its animals and flowers, man must learn to live harmoniously with them and with each other. J.M.Christensen, 1976 Contents List of tables viii List of figures ix Preface x Acknowledgements xiii 1 Human Factors 1 2 Humans: capabilities and limitations 20 3 Human-machine interaction 38 4 Work environments 70 5 Organisational issues 97 6 Occupational health 118 7 Safety 137 Epilogue 163 References 166 Annex 199 Author index 202 Subject index 207 vii Tables 1.1 Topics from the First International Conference on Cognitive Ergonomics and Engineering Psychology (1996) 8 1.2 Summary of milestones 15 3.1 Summary of controls 40 3.2 Speech and pen input: demands that can be met 46 3.3 Summary of screen design guidelines 54–5 3.4 Example of a Fitts’ list approach 60 3.5 Some disadvantages of the ‘list’ approach 61 3.6 Well-designed everyday products 66 3.7 Poorly designed everyday products 67 3.8 Some recommendations for the design process 68 4.1 Some examples of noise levels 91 5.1 Summary of recommendations for work organisation (based on Kroemer et al., 1994:329) 108 5.2 Summary of factors that influence performance (adapted from Christensen and Talbot, 1986) 109 viii Figures 1.1 Principal components of Human Factors 16 1.2 Relevant disciplines to Human Factors 16 2.1 The SHEL concept 21 2.2 Human information-processing model 26 2.3 The proposed integrated decision model 34 2.4 Smith’s (1997) three-dimensional classification of user types (reproduced with permission of the McGraw-Hill Publishing Company) 36 3.1 Human-machine interaction 39 3.2 Diagrammatic representation of the ANTEL keyboard layout 43 3.3 A fictional example of an object display 52 3.4 Mapping controls onto displays 57 4.1 Workstation dimensions diagram (from Cakir et al., 1980; reprinted with permission from IFRAS, Darmstadt, Germany (later reprinted by Wiley, UK)) 73 4.2 Example of SAMMIE display (reprinted with permission of SAMMIE CAD Ltd.) 74 7.1 ‘Swiss cheese’ accident model (based on Reason, 1990) 144 ix Preface A chair should be judged by one’s pants, a jewel by the light in a lady’s eyes, a typewriter by the hovering fingers. Time Magazine, On good design, 12 January 1959 When this quote was written, the study of human-machine interaction from a psychological perspective was in its infancy. Today, over 40 years later, we have a greater understanding of the design issues associated with human- machine interactions and work environments. This is in part due to the growing discipline of Ergonomics/Human Factors psychology. In 1996, for example, the International Ergonomics Association (IEA) had thirty-five federated and affiliated member societies. Today, this has grown to thirty- nine member societies. In 1996 there were about 17,000 ergonomists representing forty-five countries involved in professional activities under the umbrella of the IEA. The true number is likely to be higher given that the IEA does not include student members, associates or retired members. Further, some ergonomists do not belong to a professional organisation—some estimates place this at around 40 per cent. Finally, these figures are from 1996 and the overall trend has been towards an annual increase in numbers. Although the IEA includes countries from around the world, there is greater representation from some areas. Geographical areas that are well- represented include Australasia, Japan, Northern Europe, North America and Scandinavia. Although several new societies are currently being formed, there is comparably little ergonomic representation (and therefore, activity) in Africa, Latin America and the Middle East. This is important from the perspective of where the research is primarily being carried out and from where the material has been gathered in order to write this book. It has to be stated from the outset that this book has been written from a developed- world perspective. No attempt has been made to consider human-machine interactions and working conditions in communities and cultures where the emphasis is on manual labour rather than technologically driven systems. Writing such a book would indeed pose a considerable challenge. However, when considering the distribution of the world’s population, relatively few x Preface xi live in the developed world.