Contemporary Ergonomics 2000 (Contemporary Ergonomics)

Contemporary Ergonomics 2000

Contemporary Ergonomics 2000 Edited by

P.T.McCabe Centre for Human Sciences, DERA, Farnborough, UK M.A.Hanson Institute of Occupational Medicine, Edinburgh, UK and S.A.Robertson Centre for Transport Studies, University College London, UK

THE Ergonomics society

First published 2000 by Taylor & Francis 11 New Fetter Lane, London EC4P 4EE Simultaneously published in the USA and Canada by Taylor & Francis Inc 29 West 35th Street, New York, NY 10001 Taylor & Francis is an imprint of the Taylor & Francis Group This edition published in the Taylor & Francis e-Library, 2005. “To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk.” © 2000 Taylor & Francis except The cognitive cockpit: operational requirement & technical challenge R.M.Taylor, H.Howells, D.Watson © British Crown Copyright 2000/DERA Tasking interface manager: affording pilot control of adaptive automation and aiding M.C.Bonner, R.M.Taylor, C.A.Miller © British Crown Copyright 2000/DERA Adaptive automation: who has control? I.R.Craig, S.G.Russell, E.K.Flood © British Crown Copyright 2000/DERA Influence of packing methods on musculoskeletal problems among brick packers A.D.J.Pinder © British Crown Copyright 2000/HSL The development of physical selection procedures for the British Army. Phase 3: validation M.Rayson, H.Pynn, A.Rothwell, A.Nevill © British Crown Copyright 2000/MOD The global implicit measure: evaluation of metrics for cockpit adaptation M.Vidulich, G.McMillan © 2000 US Government Gender differences in primary and secondary performance during simulated driving N.M.H.Brook-Carter, T.C.Lansdown, T.M.Kersloot © 2000 Transport Research Laboratory Road sign angularity T.M.Kersloot, B.R.Cooper © 2000 Transport Research Laboratory The British Crown Copyright papers detailed above are published with the permission of the Controller of Her Majesty’s Stationery Office. Publisher’s note This book is produced from camera-ready copy supplied by the editors. 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.

iv

Every effort has been made to ensure that the advice and information in this book is true and accurate at the time of going to press. However, neither the publisher nor the authors can accept any legal responsibility or liability for any errors or omissions that may be made. In the case of drug administration, any medical procedure or the use of technical equipment mentioned within this book, you are strongly advised to consult the manufacturer’s guidelines. 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 A catalogue record for this book has been requested ISBN 0-203-30536-1 Master e-book ISBN

ISBN 0-203-34381-6 (Adobe eReader Format) ISBN 0-748-40958-0 (Print Edition)

CONTENTS

Preface AIR TRAFFIC CONTROL

xii 1

A HAZOP analysis of a future ATM system R.Kennedy, H.Jones, S.Shorrock, B.Kirwan

2

The future implementation of datalink technology: the controller-pilot perspective S.Harris, T.Lamoureux

7

Eye point-of-gaze, EEG and ECG measures of graphical/keyboard interfaces in simulated ATC H.David, F.Caloo, R.Mollard, P.Cabon, B.Farbos

12

Future system state prediction by novice and expert air traffic controllers D.Forrest, T.Lamoureux

17

Psychophysiological measures of adaptation to unfamiliar HMI in real-time ATC simulation H.David, R.Mollard, P.Cabon, B.Farbos

22

What the cognitive task analysts don’t tell you T.Lamoureux

27

ANTHROPOMETRY

32

Improving the usability of an anthropometric man-model program I.A.Ruiter

33

Anthropometric measurements in adolescents living at an intermediate altitude: the relationship between height, weight, head circumferenceand socioeconomic status M.D.Kaya, H.Yeşilyurt, B.Özkan, I.Çapoğlu, R.Akdağ

37

Relationship of upper limb postures to anthropometric variables L.W.O’Sullivan, T.J.Gallwey

43

COCKPIT DESIGN

49

Usability testing of a user interface for aircraft taxi guidance T.J.J.Bos, H.Kanis, A.J.C. de Reus, W.S.Green

50

The cognitive cockpit: operational requirement and technical challenge R.M.Taylor, H.Howells, D.Watson

57

vi

Situation assessor support system: a knowledge-based systems approach to pilot aiding N.R.Shadbolt, J.Tennison, N.Milton, H.Howells

62

Cognition monitor: a system for real time pilot state assessment K.Pleydell-Pearce, B.Dickson, S.Whitecross

67

Tasking interface manager: affording pilot control of adaptive automation and aiding M.C.Bonner, R.M.Taylor, C.A.Miller

72

The global implicit measure: evaluation of metrics for cockpit adaptation M.Vidulich, G.McMillan

77

DRIVERS & DRIVING

83

Brave new world: the vehicle autopia of the 21st century? M.S.Young, N.A.Stanton

84

Gender differences in primary and secondary performance during simulated driving N.Brook-Carter, T.C.Lansdown, T.Kersloot

89

Using observation of one traffic violation to predict an immediate second violation T.Wilson, C.Arsenault

94

ERROR & SYSTEMS

99

Analysis of shift change in the aircraft maintenance environment: findings and recommendations A.K.Gramopadhye, K.Kelkar

100

Consistency in HRA and impacts on human factors analysis R.Kennedy, B.Kirwan, B.Summersgill, K.Rea

105

GENERAL ERGONOMICS

110

A pilot study exploring the design of roles based on manufacturing process knowledge C.E.Siemieniuch, M.A.Sinclair

111

Long days and short weeks—the benefits and disadvantages K.J.N.C.Rich

116

Ergonomics needs of smallholder farmers in Mozambique D.H.O’Neill, E.J.Fraqueza

121

Are profiling beds better? Evidence from users and records J.Mitchell, J.Bennington, N.Jones,J.McClenahan

126

Human factors associated with escape from side-floating helicopters D.W.Jamieson, S.R.K.Coleshaw, I.J.Armstrong, C.Sellar, D.Howson

131

Ergonomic evaluation of work and environmental stresses on technicians working in a multimedia chip manufacturing industry in Malaysia R.N.Sen, Y.-H.Quek

136

vii

The development of physical selection procedures for the British army. Phase 3: validation M.P.Rayson, H.Pynn, A.Rothwell, A.Nevill

142

The ergonomic design of London Underground Limited’s incident reporting forms A.Whitlock, S.Layton, M.Sinclair-Williams, J.Parham

148

HCI & IT SYSTEMS

153

Research on cultural factors and interface metaphors in internet applications C.-H.Chen, C.-C.Hsu

154

Design and evaluation of a direct manipulation object for application in the postproduction special effects domain M.Hicks, J.Long, C.Borras

158

Older adults’ use of public technology M.Sheard, J.Noyes, T.Perfect

163

An assessment of the rationale & effectiveness of accelerator keys in computer applications C.C.H.Wong, K.Y.Lim

168

Can sound output enhance graphical computer interfaces? W.Morrissey, M.Zajicek

173

Adaptive automation: who has control? I.R.Craig, S.G.Russell, E.K.Flood

178

Research on Chinese computer users’ mental models in software interface design C.-H.Chen, C.-H.Chen

183

User requirements analysis for decision support systems: the question approach C.Parker

187

Why do IT systems fail to live up to expectations? a case study A.Bairsto, S.Harker

192

Development and trialling of user access to an information system for architects S.Meltzer, W.S.Green

197

Supporting universal access to information technology M.P.Zajicek, A.G.Arnold

202

Consumer acceptance of internet services M.Maguire

207

LEGISLATION

213

Ergonomics in Irish legislation V.Kelly

214

Public transport and the Disability Discrimination Act 1995 F.Bellerby

219

viii

The DSE directive: what does it mean? N.Heaton, A.Baird METHODOLOGY

224 229

How many participants: a simple statistic with some limitation H.Arisz, H.Kanis, M.J.Rooden

230

Psychophysical methods for quantifying opinions and preferences J.Engström, P.C.Burns

235

Using the web to support geographically dispersed, longitudinal usability evaluations M.Beard, C.Parker

240

The practice of triangulation I.S.MacLeod, L.Wells, K.Lane

245

MANUAL HANDLING

250

Work performed in three different modes of dynamic lifting A.D.J.Pinder, M.P.Rayson, D.W.Grieve

251

Teaching the neuromuscular approach to efficient handling and moving C.Donnelly

256

Influence of packing methods on musculoskeletal problems among brick packers A.D.J.Pinder

261

Use of human expertise in evaluating manual lifting tasks A.Genaidy, J.Beltran, A.Alhemoud, S.Yeung

266

Managing a manual handling risk assessment process J.Crowhurst, B.Catterall, G.Smyth

270

HANDS & WRISTS

275

The measurement of range of movement of the wrist: man or machine? G.E.Torrens, A.Newman

276

Hand function tests for workers exposed to hand-transmitted vibration B.M.Haward, M.J.Griffin

281

The relationship of wrist posture to discomfort during repetitive exertions E.J.Carey, T.J.Gallwey

286

Improving utensil and implement handle design through enhanced rotation and tilt G.Heavenor

291

Risk assessment of manual tipping of letter trays C.Parsons, A.Truelove

296

The evaluation of gloved and ungloved hands G.E.Torrens, A.Newman

301

ix

MUSCULOSKELETAL DISORDERS

306

Evaluating the use of single disc floor cleaners S.Hide, W.Morris, C.M.Haslegrave, O.O.Okunribido, S.C.Nichols

307

Health risks from mice and other non-keyboard input devices S.Hastings, V.Woods, R.A.Haslam, P.Buckle

312

Reducing risks for work-related musculoskeletal disorders in school nurseries C.Coole, C.M.Haslegrave

317

Psychosocial and physical factors and musculoskeletal illness in taxi drivers D.M.Anderson, R.K.Raanaas

322

Black Hawk helicopter loadmaster ergonomics P.Blanchonette, R.King, D.Crone, P.Simpson

329

Organisational issues as obstacles to intervention for musculoskeletal complaints C.G.Lawton, R.A.Haslam

334

Evaluating the risk of upper limb disorders for operators in a company using sanding and polishing equipment P.D.Bust, C.M.Haslegrave

339

PERSONAL PROTECTIVE EQUIPMENT

344

Specification of footwear for postal workers C.Parsons, A.Wray

345

What do British soldiers want from their gloves? D.McDonagh-Philp, G.E.Torrens

349

PRODUCT & WORKPLACE DESIGN

354

trends and product design P.W.Jordan

355

Sensory encounter: the codification of ‘soft’ qualities A.S.MacDonald

360

Usecues in the Delft design course H.Kanis, M.J.Rooden, W.S.Green

365

Design issues and visual impairment K.M.Stabler, S.van den Heuvel

370

Autonomy for disabled consumers: the need for systematic choice and innovation J.Mitchell, J.Bennington

375

Post office counter customer interface: a design challenge R.Ellis, C.Parsons

380

x

Revealing and responding to the needs of wheelchair consumers J.Mitchell, J.Bennington

385

Addressing pleasure in consumer products through ergonomics J.Simon, R.Benedyk

389

SEATING

394

Seating in the real world A.Baird, V.Malyon, N.Heaton

395

Drivers’ spinal responses to the effects of sitting posture T.J.Hadley, C.M.Haslegrave

400

The influence of automobile seat backrest angle and lumbar support on low back muscle activity M.Kolich, S.M.Taboun, A.I.Mohamed

405

TRAINING

410

An investigation of the effect of night vision goggles on cockpit task performance F.L.K.Tey, K.Y.Lim, Y.P.Chui

411

A redefinition of personal knowledge and a testing method to implement it D.P.Hunt

414

VISUAL DISPLAYS

419

The effect of two- & three-dimensional displays on remote crane control performance R.S.M.Quek, K.Y.Lim, Y.P.Chui

420

Airport baggage inspection—just another X-ray image? A.G.Gale, M.D.Mugglestone, K.J.Purdy, A.McClumpha

424

VIRTUAL REALITY

429

Immersive virtual reality and elderly users N.Karlsson, J.Engström, K.Johansson

430

Application of virtual reality to enhance user experience of electronic commerce (e-commerce) transactions H.Xu, K.Y.Lim, S.C.Fok

435

WARNINGS

440

The perceived hazardousness, urgency and attention-gettingness of fluorescent and nonfluorescent colours E.J.Tomkinson, R.B.Stammers

441

Increasing the conspicuity of food contents warnings E.A.Hoodless, R.B.Stammers

446

xi

Road sign angularity T.M.Kersloot, B.R.Cooper

450

Author Index

455

Subject Index

458

PREFACE

Contemporary Ergonomics 2000 are the proceedings of the Annual Conference of the Ergonomics Society, held in April 2000 at Stoke Rochford Hall. The conference is a major international event for Ergonomists and Human Factors Specialists and attracts contributions from around the world. Papers are chosen by a selection panel from abstracts submitted in the autumn of the previous year and the selected papers have the opportunity to be published in Contemporary Ergonomics. Papers are submitted as camera ready copy prior to the conference. Details of the submission procedure may be obtained from the Ergonomics Society. The Ergonomics Society is the professional body for Ergonomists and Human Factors Specialists, based in the United Kingdom, it attracts members throughout the world and is affiliated to the International Ergonomics Association. It provides recognition of competence of its members through the Professional Register. For further details contact: The Ergonomics Society, Devonshire House, Devonshire Square, Loughborough, Leics. LE11 3DW United Kingdom Tel./Fax. +44 1509 234904 e-mail. [email protected] www. http://www.ergonomics.org.uk

Air traffic control

A HAZOP ANALYSIS OF A FUTURE ATM SYSTEM Richard Kennedy1, Helen Jones2, Steve Shorrock1 & Barry Kirwan1 1Air

Traffic Management Development Centre, National Air Traffic Services Bournemouth Airport, Christchurch, Dorset, BH23 6DF, UK

2Industrial

Ergonomics Group, School of Manufacturing & Mechanical Engineering,

University of Birmingham, Edgbaston, Birmingham B15 2TT, UK

The introduction of new technology within Air Traffic Management (ATM) has lead to different types of human error being generated as the controller interacts with the system. This paper describes an approach that attempts to identify what human errors can arise and how they can be addressed by the design team. Based upon the Hazard and Operability (HAZOP) study approach, a technique was developed which could be applied to a prototype of a future ATM system. The HAZOP approach generated 87 recommendations for design improvements and the use of the technique was considered to be valuable for this and future projects in the ATM environment. Introduction Over the past few years, the aviation community has begun to recognise the growing need for updating the Air Traffic Management (ATM) system. The system itself has largely remained unchanged over the past two decades and has been effective in coping with the increases in traffic ‘year after year’. However, the ability of the system to process aircraft movements and the pressures placed upon the air traffic controller has almost hit its threshold level. A number of projects are being initiated that will help support the controller and reduce their workload. One way of freeing-up controller resources is to reduce the amount of RT (radio/telephone) time that the controller has to devote to each aircraft. A number of projects are underway to develop future ATM systems and this paper looks at a specific example of one of these projects. Assessing potential hazards at the design stage Currently, an Air Traffic Controller will use ‘flight progress strips’ in conjunction with a radar screen to control and monitor aircraft through their sector. Many new systems shift the focus away from one form of information presentation and usage (paper) to a completely different presentation medium (computer screen). Also, new systems may present additional system functionality, change the manner in which functions are implemented or actually remove some functions available to the controller. Therefore it is essential that the system is evaluated whilst it is still at the design stage so that potential operability problems and opportunities for human error can be identified and designed-out of the system. There are specialist methods to assess operability and human error potential of Human Computer Interaction (HCI) with most approaches being checklist-based and requiring human factors experts to perform the analysis. This study

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describes a different approach and reports the use of a modified Hazard and Operability (HAZOP) study approach. HAZOP has been widely used in the process industries and recently has been extended to address other types of system (e.g. programmable electronic systems, safety management systems etc.). The variants on the HAZOP approach are described in detail in Kennedy and Kirwan (1998). Hazard and Operability (HAZOP) study approach The modified HAZOP approach requires a team of experts to apply guide words (no, more, less etc.) to a visual and realistic representation of the system (e.g. screen dumps and task analysis). The HAZOP guide words that were developed for the study are shown in Table 1. A detailed description of the approach is given in Jones (1999). Table 1. HAZOP guide words and definitions

The purpose of HAZOP is to identify deviations away from the intended functioning of the system. Therefore, for instance, if the guide word ‘no’ was applied to the selection of a ‘menu’ a deviation such as ‘no heading entered into system’ would be identified. In turn, for each deviation, the group would go on to identify the consequences of the error on the system, indications that the error occurred, system defences and ways in which such an error would be recovered or reduced. HAZOP findings The HAZOP team was made up of three designers, one air traffic controller and two human factors specialists. The team spent a total of 16 hours, spanning three separate HAZOP sessions, interrogating the prototype system. Part of the study output is shown in Table 2. Overall, the HAZOP team identified a number of ‘vulnerabilities’ in the prototype system and ‘opportunities’ for error that needed to be designed out or worked around (e.g. via procedures and training). A total of 87 recommendations were generated from the three HAZOP sessions and these are classified as follows: • • • • • •

Changes to interface design and menus (34%) Improvements in user feedback on actions/inputs (25%) Training/procedures recommendations (16%) Modifications to aircraft status on screen (13%) Hardware/equipment changes (9%) Further study/future research ideas (3%)

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A HAZOP ANALYSIS OF A FUTURE ATM SYSTEM

Discussion of HAZOP approach The HAZOP approach proved surprisingly useful and productive of changes in interface design. Moreover, since the designers were not only present, but were actively involved, any design changes they thought necessary were simultaneously accepted for implementation. The HAZOP therefore had very effective impact on the design process. It was also clear from a number of the problems identified that these would have been difficult to detect without a hybrid team present. In particular each member of the hybrid team brought a unique perspective to the group process: • the designer had complete detail on how the system worked down to the software description level, and what inputs were ‘afforded’ and the consequence of those inputs; • the controller could tell and show the designers how he or she would interpret the interface at any time, and recount scenarios where something else could happen that maybe the designers had not thought about; • the Human Factors specialist could suggest error modes, possible frequencies of errors and human error and system failure detection/recovery likelihoods, and advise on HF aspects of the solutions developed following the identification of a problem. All this information was shared effectively, leading to a rich multiple-perspective on the system design and its strengths and weaknesses. The HAZOP process allowed the different parties to see the system design through other parties’ eyes, in a fairly direct way, giving a shared system understanding. On the limitations side, the approach is resource-intensive, since only a small part of the system was analysed during the three sessions. It is also, as a process, fairly dependent on good chairmanship and a collaborative attitude between the participants. Lastly, it is fair to say that this pilot study of HAZOP applied to interface design was not as structured as a conventional HAZOP would have been, but such structuring and proceduralisation of the HAZOP process in this current context can always be built in at to later HAZOP sessions. There are currently plans to continue the HAZOP work and apply it to other systems, as it was found to be of significant value by the design team. Conclusion This paper has described an approach that can be applied to the design of new systems in order to identify the potential human errors in the operation of the system. The method, based on the Hazard and Operability (HAZOP) approach, was applied to a prototype ATM system. A number of recommendations for improvements to the prototype system were made from the HAZOP and use of the approach is now being planned for other ATM projects. Acknowledgements: The authors would like to thank the design team members who took part in the HAZOP sessions, namely: Andy Webb, Tony Goodship, Stephen Pember, Brian Young, John Levesley and Andy Kilner. Also, thanks to Huw Gibson at the University of Birmingham for his supervision of the MSc project.

Table 2. Example of HAZOP analysis outputs

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A HAZOP ANALYSIS OF A FUTURE ATM SYSTEM

The opinions in this paper are those of the authors, and do not necessarily represent those of NATS or other companies involved in this research References Jones, H. (1999) A modified HAZOP analysis of a future air traffic control system. Confidential MSc Thesis, Industrial Ergonomics Group, School of Manufacturing and Mechanical Engineering , University of Birmingham, September. Kennedy, R. and Kirwan, B. (1998) Development of a HAZOP-based method for identifying safety management vulnerabilities in high risk systems. Safety Science, 30, 3, 249–274.

THE FUTURE IMPLEMENTATION OF DATALINK TECHNOLOGY: THE CONTROLLER-PILOT PERSPECTIVE Sarah Harris1 & Tab Lamoureux 1College 2Air

of Aeronautics, Cranfield University, Cranfield, Bedfordshire MK43 0AL

Traffic Management Development Centre, National Air Traffic Services, Bournemouth Airport, Christchurch, Dorset BH23 6DF

In the near future, Air Traffic Control and a majority of aircraft will be equipped with datalink technology. However, in addition to its anticipated benefits, some concern has been raised regarding the use of datalink within certain contexts. For this reason, the perspectives of controllers and pilots on five main datalink tools and their use within different flight phases and control areas were gathered. Perspectives were based on the potential impact datalink could have on their workload, situation awareness, human error and crew resource management, compared to present operations. The method included the use of self-completion questionnaires, developed through preliminary datalink interviews. Introduction Due to a continued increase in air traffic, current radio telephony (R/T) channels have become over crowded and thus inefficient in coping with the existing demand for information transfer. The development of datalink (DL) technology has therefore focused on reducing the burden placed on R/T channels and enhancing the overall effectiveness of the communications, surveillance and navigation network. DL will constitute the implementation of digitised communication facilities via Very High Frequency transmitters, Secondary Surveillance Radar and satellite, which will be accessible for both the controller and pilot through some kind of visual display unit. This will enable the controller and pilot to digitally send and receive flight information, Air Traffic Control (ATC) instructions and other general pre-formatted communication messages between themselves, airline offices and other ATC Centres, with the press of a button. In general, DL implementation is anticipated to improve overall human performance compared to present R/T procedures. However, numerous studies (both in an existing DL context and in trials for European DL), have found that specific DL tools and facilities have had an adverse impact on human performance, compared to present operations. For example, problems are anticipated with the use of DL in certain flight phases and ATC environments, such as the busy Terminal Manoeuvring Area (TMA). Other difficulties may exist concerning inherent problems with automation in general. During DL trials, Shingledecker (1992) reported that controllers were forced to revert to R/T during the final approach sector (where tasks were *Current address: Avionic Systems Engineering, BAE Systems, York House, PO Box 87 Farnborough Aerospace Centre, Farnborough, Hampshire GU14 6YU

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THE FUTURE IMPLEMENTATION OF DATALINK TECHNOLOGY

Table 1. Interference Caused by Similar Input Modalities (Nijhuis, 1993)

significantly more time constrained and demanding), as DL was deemed too slow or complex to maintain control in such a highly tactical airspace. In addition, one study showed that pilots also found DL to be operationally unacceptable, due to high task densities and small task completion windows in a terminal context (Reynolds and Neumeier, 1991). This was further supported in a review by Kerns (1991), where DL operations were found to increase workload and thus be unacceptable to pilots during both the departure phase (from take off until 2,000 ft) and the arrival phase (from 10,000 ft and below). Most of the difficulties and anticipated benefits associated with DL are due to the potential impact it may have on various human factors issues. One such example is the change in input modality from auditory to visual channels. This may significantly impact a controller’s capacity by overloading their perceptual resources and introducing the possibility of resource interference (see Table 1). Consequently, this study focuses on four significant human factors pertinent to DL research; workload, situation awareness, human error and crew resource management. The five main types of European DL included in the research were the Aircraft, Communication and Reporting System (ACARS), the Automatic Dependent Surveillance (ADS), Controller-Pilot Datalink Communications (CPDLC), Mode Select (Mode-S) and the Flight Information Service (FIS). Other more general aspects of DL were also covered, such as interface options and usage variability. An analysis of the potential impact of the DL items on the human factors across tasks (controllers and pilots) and contexts (TMA and ‘cruise’ phase), allowed a clear indication of which DL items need further research and development before their implementation. Methodology A self-completion questionnaire was developed to evaluate controller opinions across different types of control areas (i.e. oceanic, terminal and area control) and pilot opinions across different types of flight phases (i.e. from a ‘cruise’ perspective and a ‘TMA’ perspective). These questionnaires were formulated by compiling lists of DL items, which were segregated into ‘pilot only’ items (12), ‘controller only’ items (9) and ‘joint controller-pilot’ items (40). These were then transformed into questions, along with an appropriate answering structure that required participants to comment on whether they thought an item would have a negative, positive or have no effect at all on the four human factors, compared to their current operations. These questions were initially used in preliminary semi-structured interviews, then administered as draft questionnaires, and following feedback, were amended and sent out as final self-completion questionnaires. The final questionnaires were a ‘controller only questionnaire’, a ‘pilot only questionnaire’ (to be answered from a TMA perspective) and a ‘pilot only questionnaire’ (to be answered from a cruise perspective). The controller only questionnaire consisted of ‘controller only’ DL items and mixed items (applicable to controllers and pilots), whereas both pilot questionnaires contained the same mixed items, along with ‘pilot only’ items. A total of 100 ‘controller questionnaires’ were sent to Oceanic/Airways Control, Area Control and Terminal Control and 600 ‘pilot questionnaires’ (300 TMA, 300 Cruise) were delivered to British Airways Captains, Senior First Officers and First Officers.

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Discussion Responses were analysed between controllers and pilots in general and also between those who work (or were allocated) in the ‘cruise’ phase (cruise pilots and oceanic/area controllers) and those in the ‘TMA’ phase (terminal controllers and TMA pilots). Overall, results indicated no significant differences between the ‘cruise’ and ‘TMA’ controllers on any of the ‘controller only’ DL items and significant differences were only found between pilot perspectives on two of the ‘pilot only’ DL items. Table 2. Consensus Opinions towards Certain Datalink Items

n/a: Not applicable to that group (i.e. either a pilot only or a controller only question)

However, some of the descriptive group means were also examined, despite non-significant results. This was deemed imperative as a non-significant result often indicated a ‘consensus’ in opinion towards certain DL items. Only the means which were either above +.5 or below −.5 were described, in order to highlight any extreme preferences or dislikes by controllers and pilots (respondents indicated +1 for a positive effect, 0 for no effect and −1 for a negative effect). Table 2 includes some of the DL items that controllers and pilots had either extremely negative (neg) or positive (pos) opinions towards (a consensus), which may explain why no significant differences were found. As illustrated in Table 2, the ability to use DL for transparent transfers, multiple clearances, strategic and non-control information, was considered a particular benefit by all controllers and pilots. However, the controller’s ability to hear the intonations of the pilot’s voice and the pilot’s lack of awareness of other aircraft, was considered to have a potentially negative effect on their situation awareness and human error rate. Despite these disadvantages, most of the controllers and pilots shared a consensus that DL would be beneficial to their workload, due to improvements to non-critical aspects of their work. With reference to the joint controller-pilot sections, significant differences were found across and between both TMA and cruise groups and controllers and pilots. Table 3 includes the DL items where significant differences across groups were found. However, in the joint sections, only the outcomes with significant main effects are reported. These are summarised by indicating which one of the groups were significantly more positive towards that item with respect to one or more human factors (a p would mean

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THE FUTURE IMPLEMENTATION OF DATALINK TECHNOLOGY

Table 3. Significant Differences in Opinions across All Groups

c-p: controller or pilot t-c: TMA or cruise phase n/a: Not applicable to that group (i.e. either a pilot only or a controller only question)

the main effect was due to pilots being significantly more positive towards that item). As with Table 2, overall extremely positive or extremely negative responses are also included. It was apparent that a majority of the main effects found were with relation to the positive responses by pilots compared to controllers, especially pilots from the TMA phase (see Table 3). Results indicated that pilots were favourable towards a message transaction time of 6–12 seconds, especially with reference to the cruise phase. However, terminal controllers thought this time limit was unacceptable. As TMA operations are restricted by small task completion windows, it was anticipated that the TMA group would be less favourable towards this time frame compared to the cruise group (Shingledecker, 1992). With respect to automatically triggered messages with no human input, pilots also found this facility to be beneficial (regardless of flight phase). Controllers however, thought this would have a particularly negative impact on situation awareness, especially in the TMA, as this is when they would normally speak with the aircraft. Ultimately, this would reduce the ‘perception of elements in the current situation’ (Endsley, 1988), thus impacting the first level of situation awareness. Additionally, controllers were extremely negative concerning the issue of having to retry if a message failed or having to notice if no response was received from a message sent, especially with respect to workload. The prospect of having to retry due to automation failure would add to the complexity of the task, thus increasing the workload of the controller. Items of particular benefit were the pre-notification idea, transfer of data authority facility, Departure Clearance Service and the use of DL for clearances in general. Although pilots were significantly more positive towards these items compared to controllers (on most of the human factors), controllers also deemed these items to have a potentially beneficial effect, especially with respect to workload and crew resource

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management within terminal control. However, one DL issue that was considered to have a negative impact on operations by both pilots and controllers, was the fact that pilots using DL will not be able to hear other ATC conversations with other aircraft. Both pilots and controllers thought this would have an extremely negative impact on human error and situation awareness, especially within the TMA. Even without DL, situation awareness errors are often associated with being unable to comprehend the ‘big picture’. Therefore, if DL reduces the ability to comprehend the ‘big picture’ (according to respondent’s opinions), then these types of errors may increase. To conclude, pilots from the terminal context thought DL could have a potentially positive impact overall, but mainly on non-critical operations. Conversely, controllers expressed particular concern over the use of DL in a terminal context. As DL will have to be used by both controllers and pilots in certain contexts (such as the TMA), this could pose problems for its future flexibility. Therefore, as well as researching into the actual impact DL may have on terminal control critical and routine operations, increasing the awareness of the benefits of using DL within terminal control, is of particular importance before its implementation. References Endsley, M.R. 1988, Design and Evaluation for Situation Awareness Enhancement. Proceedings of the Human Factors Society 32nd Annual Meeting, 1, 97–101 Kerns, K. 1991, Data-Link Communication Between Controllers and Pilots: A Review and Synthesis of the Simulation Literature. International Journal of Aviation Psychology. (Lawrence Erlbaum Associates), 1 (3), 181–204 Nijhuis, H.B. 1993, Workload in Air Traffic Control Communication. In E.J.Lovesey (Ed.) Contemporary Ergonomics: Proceedings of the Ergonomics Society’s 1993 Annual Conference, Edinburgh, Scotland. (Taylor and Francis), 284–289 Reynolds, M.C. and Neumeier, M.E. 1991, Mode-S Data Link Pilot-System Interface: A Blessing in De Skies or a Beast of a Burden? Sixth International Symposium on Aviation Psychology, 1, 154–159 Shingledecker, C.A. 1992, Controller Evaluations of ATC Data Link Services. Society of Automotive Engineers Technical Paper Series. Report Number 922027

EYE POINT-OF-GAZE, EEG AND ECG MEASURES OF GRAPHICAL/KEYBOARD INTERFACES IN SIMULATED ATC Hugh David1, F.Caloo1, R.Mollard2, P.Gabon2 & B.Farbos2 1Eurocontrol 2Laboratoire

Experimental Centre, 91222 Bretigny-sur-Orge, Cedex, France

de l’Anthropologie Applique, 45 Rue des Saints-Peres, 75270 Paris, France

To assess the utility of eye movement recording for the assessment of different ATC operating methods, its relation to other electro-physiological measures and their sensitivity to task difficulty, 8 controllers carried out four TRACON II exercises using a graphic and a keyboard interface in light and heavy traffic. An iView head-mounted eye-tracking device was used. EEG/ EOG and EKG were also measured, and on-line observations recorded using the Noldus Observer System. Significant events during the exercises were also identified for detailed analysis. Introduction A series of small-scale Real Time (RT) simulations of Air Traffic control (ATC) has been carried out as reported previously (Cabon et al, 1997, 1998, David et al, 1998, 1999), to evaluate the use of psychophysiological measures to measure the effects of performing ATC on controllers. These simulations used a simple Wesson International TRACON II Autonomous ATC simulator. On the basis of the findings of these simulations, selected psychophysiological and self-assessment measures were applied to a RT simulation, as described elsewhere in this volume. Continuing the Eurocontrol Experimental Centre policy of preliminary small-scale investigations, attention was turned to the measurement of eye-movement (Point of Gaze). This technique has been used on other occasions for investigations in real life ATC (Bouju and Sperandio, 1979, Leguillou et al, 1981) and in RT simulations, (David, 1985), but without corresponding measures of psychophysical strain. Aims This study was undertaken in order to:1. Provide experience in applying Eye Point-of-Gaze measurement in a Real-time simulation. 2. Provide experience of the simultaneous application of electrophysiological measures. 3. Investigate the sensitivity of these measures to different control devices in light and heavy traffic. 4. Investigate the utility of the Noldus Observer system for ATC observation. 5. Investigate controllers’ eye-movements prior to undesirable events.

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Method Eight experienced but not currently practising Air Traffic Controllers carried out simulation exercises using the TRACON II Autonomous Air Traffic Control (ATC) simulator at Eurocontrol Experimental Centre, (EEC), Bretigny, France. Each controller undertook four exercises, controlling 15 and 30 aircraft entering in 30 minutes, using graphic (trackball/pointer/windows) and coded keyboard input methods. The two lighter loaded exercises were carried out on one afternoon, following some preliminary training exercises, and the more heavily loaded exercises were carried out on the following afternoon, to minimise circadian rhythm problems. The orders of presentation of samples and input methods were permuted to minimise overall bias. The traffic level for the heavier sample was deliberately chosen to exceed the controllers’ expected capacity, in order to produce a significant number of ‘errors’: missed approaches (where an aircraft is not correctly positioned for landing), missed hand-offs (where an aircraft is not transferred to the next sector in time), conflicts (where aircraft approach within 3 NM without 1000 feet vertical separation) and even collisions. Measures The controllers’ left/right frontal Electroencephalogram (EEG) and Electrocardiogram were recorded using a Vitaport psychophysiological recorder. The point of gaze was recorded using a Sensomotoric Instruments iView head-mounted eye-tracking device. Point-of-Gaze video recordings were obtained for all exercises. (No interference was experienced between the EEG and the eye-tracking helmet—in fact the lightweight cycle helmet helped to secure the EEG electrodes firmly in place.) A preliminary analysis was carried out using the Noldus Observer on-line, an observer recording major shifts of attention. Significant events during the exercise were noted. The TRACON II simulator provided an overall score for each exercise, with numbers of the “errors” mentioned above. (Unfortunately, the TRACON II simulator stops if a collision occurs, and destroys the records of the controller concerned.) The Controllers filled in fatigue measurement instruments before and after exercises, and completed the NASA-TLX instrument after each exercise. They also completed a post-simulation questionnaire after the last exercise. Analysis Eye Movements Aircraft entered the simulation over a 30-minute period, and took about 15 minutes to complete their flights. There was an initial rise in activity, a busy period and a final tailing-off of activity. Eye-movement analysis was therefore confined to the busiest 20 minutes of each simulation. Initially, the location, duration and frequency of eye-movements were analysed on a minute-by-minute basis. The TRACON II screen (400 mm×300 mm) is divided into a Radar display (Top left, 275 mm square), flanked by a strip bay (Right, 125 mm wide), containing strips (15 mm deep). Pending strips, relating to aircraft not yet under the controller’s control, appear above Active strips. Strips appear in the Pending list, are transferred to the Active list automatically on acceptance, and are removed automatically from that list when the aircraft lands or leaves the area. A communications window (25 mm deep), below the radar, shows in text form the verbal messages generated by the system from the controller’s input and simulated pilots and adjacent controllers. When operating in the track-ball/pointer (Graphic) mode, pop-up windows

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of varying sizes and shapes (about 50 –80 mm in either dimension) appear, providing choices of instructions and complementary information. The mean number of fixations per minute was approximately 15 per minute for the graphic mode, and 25 per minute for the keyboard mode. In keyboard mode, the controllers switched frequently between the keyboard, the active strip area and the radar. Controllers using the graphic interface spent about 57 percent of their time looking at the radar, 17 percent looking at the active strips and 17 percent looking at ‘pop-ups’. Controllers using the keyboard interface spent about 47 percent of their time looking at the radar, 20 percent looking at active strips and 20 percent looking at the keyboard. Surprisingly, the traffic load made no significant differences in the duration or number of fixations, for either control mode. Electroencephalography The estimated thcta-rhythm power rose for higher traffic load in the keyboard mode, as might be expected. In the graphic mode, however, it fell. ECG- Mean Rate For both modes, the variability of heart rate (sinusarythmia) fell for higher task loads. There was a significant negative correlation between sinusarythmia and the number of fixations for radar, active strips, and keyboard, and between sinusarythmia and the time spent looking at the radar. NASA-TLX There were significantly higher scores for the mental, physical and temporal demand and effort sub-scales of the NASA-Task Load Index for heavier traffic load. Performance The overall TRACON score was higher for higher traffic load, although the deliberate overloading of controllers in the high traffic load produced variable scores. Specific error frequencies showed a more complex pattern. There were more separation losses in the keyboard mode, suggesting less situational awareness. There were more handover errors in heavy task load conditions, suggesting that controllers may decide to ‘shed’ this task under time stress, and more missed approaches in the graphic control mode, which may be attributed to the lower precision of the graphic methods for height and speed allocation. Controller Orders There were no significant differences in the numbers of orders per minute—even between high and low traffic load conditions. Discussion This was an initial feasibility study, which should be repeated with larger numbers of subjects. The observed results can only be regarded as tentative, but are indicative.

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The only problems encountered with the head-mounted iView equipment were that the tracking was lost when the controller was looking downwards, as the upper eyelid tends to fall as he does so. This problem is exacerbated when bifocal or progressive lenses are worn, since these force the controller to tilt his head back to read print. EEG electrodes were applied with collodion, and the converted bicycle helmet used by the iView system helped to hold them in good contact. Only one controller expressed discomfort at this combination. Calibration of the equipment presented some problems. A blank panel with a grid of reference points was presented to the controller, who was asked to look at these points while the computer-based calibration was carried out. Normally, this required about five minutes, but on some occasions calibration had to be repeated several times. It was important that the controller adopted his true working posture, rather than leaning back from the screen. (Controllers when working tend to lean towards the screen when solving problems, and to lean back after finding solutions.) The I-view system presents the point-of-gaze as a point on a video image taken from a head-mounted camera. This permits free head movement but requires costly and slow manual analysis. The video-records incorporating the controller’s eye movements provide the opportunity to examine in detail exactly where the controller’s attention was directed before significant events, such as failures to maintain separation, failures to hand over aircraft to the next sector and so on. These analyses are particularly laborious, and are currently being completed. An initial hypothesis, that controllers did not see that an aircraft was due to be handed over to the next sector, because they were looking at another part of the screen, does not appear to be supported. It appears that either they were too busy, or they had not realised that an attempt to hand over had been rejected. The integration of psychophysiological, eye-movement and operational data on a minute-by-minute basis was practical and effective. It is not yet practical to identify which aircraft image or strip is being looked at, or to separate EEG signals according to the direction of gaze, so that no direct information on the lateralisation of brain functions has been obtained. Conclusions 1. Eye Point-of-Gaze measurement was successfully applied in this Real-time simulation. 2. Electrophysiological measures were applied successfully at the same time as these measures. Results of ECG, EEG and Eye Movement were combined (on a minute-by-minute basis.) 3. Eye Movement measurements were sensitive to the interface mode. Psychophysiological measures were sensitive to the interface mode, and to traffic load. 4. The Noldus Observer system can be usefully applied to the direct observation of a single controller, and to the analysis of video records. Some method of time-sharing or sampling should be developed for the observation of many controllers. 5. The investigation of controllers’ eye-movements prior to undesirable events is continuing, but initial observations do not support the hypothesis of ‘over-concentration. References (Paper copies of EEC Notes and Reports are available from the address above. Recent Notes and Reports are available at the EEC Web-site (www.eurocontrol.fr)) Bouju, F. and Sperandio, J-C, 1979, Analyse de l’activite visuelle des controlleurs d’approche. Rapport C.O. 7911 R59. INRIA France

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Cabon, P., Mollard, R., Cointot, B., Martel, A. and Beslot, P. 1997, Elaboration of a method for the psychophysiological states of Air Traffic Controllers in Simulation EEC Report No. 323 (Eurocontrol Experimental Centre, Bretigny-sur-Orge, France) Cabon, P., Farbos, B., Bourgeois, S., R., Cointot, B. and Mollard, R. 1998, Objective evaluation of the learning process of controllers adapting to a new HMI for ATC EEC Note No. 16/98 (Eurocontrol Experimental Centre, Bretigny-surOrge, France) David, H., 1985, Measurement Of Air Traffic Controllers’ Eye Movements in Real Time Simulation. EEC Report No. 187 (Eurocontrol Experimental Centre, Bretigny-sur-Orge, France) David, H., Cabon, P., Bourgeoise-Bougrine, S. and Mollard, R., 1998 Psychophysiological Measures of Fatigue and Somnolence in Simulated Air Traffic Control, In M.A. Hanson (ed.) Contemporary Ergonomics 1998, (Taylor and Francis, London) 427– 433 David, H., Farbos. B., Bourgeois, S., Cabon, P., and Mollard, R., 1999 Psychophysiological Measures of Adaptation to an unfamiliar HMI in Simulated Air Traffic Control, In M.A.Hanson, E.J.Lovesey and S.A.Robertson, (eds.) Contemporary Ergonomics 1999, (Taylor and Francis, London) 12–16 Jasper, H.H., 1958, The 10–20 electrode system of the International Federation, Electroencephalography and Clinical Neurophysiology, 10, 371–376 Kramer A.F., Donchin E. and Wickens C.D. 1987, Event-Related Potentials as indices of mental workload and attentional allocation, In Electrical and Magnetic Activity of the Central Nervous System: Research and Clinical Applications on Aerospace Medicine. AGARD Conference Proceedings No. 432, pp 14–1 to 14–14 Leguillou, M., Halliez, B. and Nobel, J., 1981, Etude du Travail du controleur Organique au CRNA/Nord Par Analyse de la saisie visuelle, CRNA R 81/22 (DNA, Paris)

Future System State Prediction by Novice and Expert Air Traffic Controllers Damien Forrest1 & Tab Lamoureux2 1Psychology 2Air

Department, University College London Gower Street, London, WC1E 6BT

Traffic Management Development Centre, National Air Traffic Services Bournemouth Airport, Christchurch, Dorset, BH23 6DF

Abstract

The purpose of this study was to examine how well Novice and Expert Air Traffic Controllers could predict future conflict situations. Measures of conflict detection and confidence were established using signal detection methodology and calibration statistics. Significant differences were found between groups in their ability to identify conflict situations and both groups exhibited levels of over-confidence in their judgments. The type of conflict also showed a significant impact upon the controllers’ judgments, with side-on conflicts being the most difficult to predict. The results have implications for the training of the controllers and a number of recommendations are made. Introduction As the amount of air traffic continues to escalate, Air Traffic Management (ATM) systems endeavour to maintain their established records of safety and efficiency. Despite the increasing use of technology-based support systems within ATM, it is still the individual operators of the system that maintain primary control and who are ultimately responsible for the safe management of air traffic. Hence, the more macro-goals of the ATM system, i.e. the provision of a safe and expeditious air traffic control or advisory service (MATS— Part I), is reflective of the level to which the more micro-goals of the system are achieved, i.e. the skills, abilities and limitations of the individual operators; irrespective of the system’s technological power. The task success is contingent upon many factors. Controllers must be able to detect, identify and assimilate large amounts of data from competing sources of information, to make accurate judgments and timely decisions within this highly complex and dynamic task environment (Lamoureux, Cox and Kirwan, 1999; Smolensky, 1999). The dynamic nature of the task has a considerable impact upon the judgments and decisions made by the controllers (Kerstholt, 1993). With a task environment that continually changes, one of the largest dangers to the system is therefore the failure of the controllers to estimate and prepare for future system states. For example, based upon the controller’s awareness of the current situation, it is their skill in identifying future potential problems before they occur and to provide appropriate solutions to these problems, which makes this predictive ability one of the most important aspects of the integrity of the system. Notwithstanding the technological support, the importance of the training for this ability is evident. There is increasing use in ATM of technology-based support systems to help maintain this awareness and to aid in the prediction of future system states (e.g. the Short Term Conflict Alert system). However, there

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are still concerns about how these systems currently (and in the future will) affect the controllers (Kirwan, 1999). Hence, (for the moment) future system predictions are still made at the ‘sharp-end’ by the controllers themselves. It has been suggested that errors in future state prediction are linked to a failure of the controller to maintain awareness of the task environment, with failures in state awareness forming the largest category of error in aviation (Jones and Endsley, 1996). One form of error identified is where the controller has full awareness of what is going on (e.g. they have detected and identified all the relevant aircraft) but, according to Jones and Endsley, have possessed a poor mental model for predicting the consequences of any actions taken into the future time-frame; which may result in a loss of separation (i.e. a potential conflict situation). Another prediction-associated error investigated within this study is proposed. This is termed an operational side-effect error (OSEE): the failure of the controller to predict the unforeseen and undesired consequences of their actions, resulting in a loss of separation. This is not, as Jones and Endsley perhaps would suggest, because of an inappropriate mental model—it is the prediction judgment itself that is unsound. For example, a controller has identified a potential conflict between aircraft A and aircraft B, who are both travelling at the same flight-level. Before taking any action, the controller re-assesses the situation in light of their planned actions. After which instructions are given to aircraft A to drop to a lower level, thus, avoiding the potential conflict situation with aircraft B. However, shortly after aircraft A loses separation with aircraft C, which was climbing through the flight level given to aircraft A. Although aware of the existence of aircraft C, the controller failed to identify it as being a potential problem. The question is, if the controller had awareness of aircraft C and it’s intentions, why then did they fail to identify the secondary conflict? In order to answer these types of questions, it would be useful to establish a measure of the controller’s predictive ability. Previous research within ATM has been arguably unsuccessful in the identification of the underlying judgmental aspects of this predictive ability. Although it is suggested that failures in prediction may be associated with a deficit in the controller’s state awareness, the global awareness measures often used to establish this tell us very little about the quality of the prediction judgment itself (Endsley, 1988; Jones & Endsley, 1996). SA is typically measured by the controller’s perception and recall of factors within the task environment, not on their ability “…to know what the hell to do about it” (Smolensky, 1999). Hence, as a tool for research or training, global measurement techniques are limited in their contribution to an understanding of these prediction errors. The aims of this research were twofold: Firstly, to measure the ability of the controllers to predict future system states; and secondly, to investigate the possible factors surrounding the associated errors in future system state prediction. Methodology Six males and one female student air traffic controllers (SATCs) and five male instructors were presented with a series of six static-based experimental scenarios. Each scenario was based on an area control task and contained 5, 6, 7 or 8 aircraft (on the radar display) and between 5 and 7 aircraft on the flight progress strips (i.e. aircraft due to enter the sector). Each scenario had number of potential conflicts: These were either, (a) primary conflicts, in which aircraft would lose separation if no action were taken; or (b) secondary conflicts, which if inappropriate actions were taken in dealing with a primary conflict, a secondary loss of separation would occur.

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A semi-structured interview was used to establish primary and secondary conflict identification data. Further, for each pair of aircraft discussed the participant was also asked to give an estimate of the closest point of approach (CPA) between the aircraft, together with a measure of confidence in that decision. Results Conflict identification was measured using multidimensional detection theory (see Swets, 1996). From these data the mean group d-prime and beta scores were computed (see table 1). Results showed that experts showed a greater ability to identify overall conflict situations than students (t (8)=−2.541, p