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Human factors guidelines and methodology in the design of a user-computer interface: A case study
design of such systems. Project results are described, and examples of currently used displays presented and analysed. Improved and entirely new power system control centre displays are presented along with the rationale for their design. 19.2.20 (105357)
Bainbridge, L. VDT/VDU interfaces for process control. In: New methods in applied ergonomics, J.R. Wilson, E.N. Corlett and I. Manenica (Eds). Taylor and Francis, London, 1987, pp 9 7 - 1 0 5 . Computer-generated displays on Visual Display Units/Terminals raise some interesting new ergonomics problems. The flexibility of the display format gives greater freedom of design, but there are also new limitations, because displays have to be shown on a small surface areas, so only some of the potential data can be seen at one time. In this paper the dimensions to be considered are briefly outlined. 19.2.21 (105393) Frohlich, D.M. On the organisation of form-filling behaviour. InfDesign J, 1986, 5 (1), 43-59. Given the ubiquity of transactional forms it is surprising that so little is known about the dynamics of the formfilling activity itself. This paper reports a detailed observational study of the reading and routeing activities of subjects as they filled in a DHSS postal claim form. The results of this study suggest a number of broad principles which appear to govern the interaction of subjects with the written material of the form. The local application of these principles in the context of a form-filling history can account for idiosyncrasies in form-filling behaviour. This interpretation is consistent with the view that form-fiUers employ a conversational model of form-filling despite the static nature of the paper medium through which it is conducted.
ware system for problem purposes. Software ergonomics discusses issues concerning the adjustment of software systems to their human users. A model for user interfaces has been proposed by IFIP WG 6.5. This model allows a detailed description of several aspects of a user interface by means of four different interface types. These aspects can be analysed independently. The adaptation of a software system to a working environment is described by the so-cailed 'tool-interface'. This interface comprises the users' access to the software tools of the system. A user-adequate command language should implement a high-quality tool interface. Requirements are established to which the design of the tool interface must adhere. Typical problem situations are illustrated by examples gathered while developing a conception of a user interface for the UNIX operating system.
Display and control design 19.2.23 (105439)
Hodes, D., and Akagi, K. Study, development and design of a mouse. In: A cradle for human factors. Proc Human Factors Soc 30th ann meeting, Dayton, Ohiol 29 S e p - 3 Oct, 1986. Human Factors Soc, Santa Monica, Cal, Vol 2, 1986, pp 9 0 0 - 9 0 4 . A series of research studies was conducted to develop design criteria for a general purpose mechanical input device. The design criteria and parameters were established with ergonomics studies which included task analysis, competitive analysis and human-performance testing. By taking a leadership role in the production issues, human factors engineers were successful in having the results of their research implemented into a new design. This report is a case study which offers some insight into methodological and design issues associated with producing an ergonomically designed product.
19.2.22 (105376)
Hoffmann, C., and Vaider, W.
19.2.24 (105440~
Command language ergonomics. In: Foundation for human-computer communication, K. Hopper and I.A. Newman (Eds). North-Holland, Amsterdam, 1986, pp 2 1 8 - 2 3 4 .
Arnaut, L.Y., and Greenstein, J.S. Optimising the touch tablet: The effects of control-display gain and method of cursor control. Human Factors, 1986, 28(6), 7 1 7 - 7 2 6 .
For a broad range of applications, command languages provide very efficient access to the tools of a software system. The complexity of many systems leads, however, to a gap between the functions offered by the system and those tools actually used by its users. The design of command languages has to solve this problem in a way that provides means for user interfaces which allow both efficient and adequate utilisation of the soft-
The purpose of this research was to assess the effects of control-display gain, method of cursor control, and target size on target selection performance with a touch tablet. In addition, an attempt was made to determine a definition of control-display gain that would generalise across different control-display combinations. The results indicated that a relatively low gain (approximately 0"8 to 1"0) resulted in more efficient target selection
performance than did higher or lower gains. An absolute mode of cursor control, in which the cursor appears on the display in a position corresponding to the location of the finger on the touch tablet, resulted in faster selection rates and fewer target entries prior to confirmation than did a relative mode of. cursor control. Selection of large targets was faster and more accurate than selection of small targets. Alternative explanations for performance differences are discussed. 19.2.25 (105448)
Breitmaier, W.A., Waldrop, G.P., and Lazo, J. Human factors engineering analysis of Marine Corps night attack aircraft. In : A cradle for human factors. Proc Human Factors Soc 30th ann meeting, Dayton, Ohio, 29 S e p - 3 Oct, 1986. Human Factors Soc, Santa Monica, Cal, Vol 2, 1986, pp 8 6 1 - 8 6 4 . The US Marine Corps has proposed sensor and display improvements to provide night attack capability for the AV-8B and F/A-18 aircraft. The aircraft enhancements include the addition of a forward looking infrared sensor displayed on a new raster head-up display, night vision goggle compatibility, and a colour multipurpose display. A human factors engineering analysis was performed to identify the human factors impact of the cockpit changes involved. Included in the analysis were a literature review, interviews with pilots, design considerations review, and development of recommendations based on both human factors standards and lessons learned from similar projects. The primary areas researched were : cockpit lighting, colour displays, and night vision sensor utilisation. 19.2.26 (105462)
Richards, R.E., Gilmore, W.E., and Haney, L.N. Human factors guidelines and methodology in the design of a usercomputer interface: A case study. In: A cradle for human factors. Proc Human Factors Soc 30th ann meeting, Dayton, Ohio, 29 S e p - 3 Oct, 1986. Human Factors Soc, Santa Monica, Cal, Vol 2, 1986, pp 1073-1077. In this case study, human factors personnel were requested to participate in a project team of programmers and operations specialists to design a cathode ray tube (CRT) display system for a complex process control application. This presentation describes the process and benefits obtained by incorporating human factors guidelines and methods in system design. Standard human engineering guidelines and techniques were utilised by the project team. In addition, previously published documents and research
Applied Ergonomics
June 1988
159
findings sponsored by the United States Nuclear Regulatory Commission (USNRC) were used. Preliminary tasks involved a review of the draft plant procedures. Then, interviews with operators were conducted to establish the initial information for the displays. These initial requirements were evaluated against existing guidelines and criteria to determine the optimal presentation formats. Detailed steps of the approaches used, design decisions made, and trade-offs that resulted in the final user-acceptable design are discussed. 19.2.27 (105463)
Roscoe, S.N. VTOL control and display design : Principles and methods. In: International reviews of ergonomics, Vol 1, D.J. Oborne (Ed). Taylor and Francis, London, 1987, pp 135-158. This review covers an area of aircraft control and display research leading to the application of a set of ergonomics design principles to the problems of vertical and translational instrument flight. A system approach to design is interwoven with an holistic approach to experimentation. VTOL missions are analysed to reveal deficiencies in conventional instrumentation, to identify information and control requirements, and to configure and simulate a generic VTOL control and display system. Through a sequential programme of experimentation involving fractional-factorial screening designs and centralcomposite response surface mapping, critical dynamic control and display design parameters are optimised.
Workplace and equipment design 19.2.28 (105479)
Chan, W.L., Pethick, A.J., and Graves, R.J. Ergonomic implications in the design of an engine assembly line. In: Contemporary ergonomics 1987, E.D. Megaw (Ed). Taylor and Francis, London, 1987, pp 1 4 0 - 145. An ergonomics study, simulating four tasks on a new assembly line, indicated that their design would result in the target line cycle times not being achieved. Postural analysis also indicated a high potential risk of back pain problems. The proposed reduction in the number of repair loops on the line could increase repair times and had implications for the selection and training of repairmen. An ergonomics redesign of the workstations recommends changes in the workspace layout, the presentation of workpieces and component stock feeding systems which would improve the
160
Applied Ergonomics
June 1988
operator's health, as well as reducing the process cycle times for the tasks.
moment at L5-SI were used as parameters of back load. The results showed that a newly designed shovel, 19.2.29 (105481) characterised by a relatively large Das, B. curvature, is an acceptable alternative An ergonomic approach to designing a to the standard shovel. However, none manufacturing work system. In t J of the test shovels appeared to be I n d u s t Ergonomics, 1987, 1(3), 231 designed in the best possible way for 240. digging tasks in sand with very high This paper highlights the methodology thrusting resistance. that was applied systematically to 19.2.32 (105513) incorporate ergonomics principles and Robertson, S., and Porter, J.M. data to the design of a manufacturing Motorcycle ergonomics: An work system. The manufacturing task exploratory study. In : Contemporary comprised drilling four holes on a ergonomics 1987, E.D. Megaw (Ed). prepared steel plate. The components Taylor and Francis, London, 1987, of the manufacturing work system pp 173 178. included: manufacturing task, powerfeed drill press, jig, fixture and other This paper describes a questionnaire equipment, workplace layout, operator survey of the ergonomics problems of training and (hard) production motorcycles, and a pilot experimental standard and'feedback. The ergonomicstudy of the preferred riding position ally designed manufacturing work for motorcyclists. A high incidence of system proved to be effective and discomfort was evident and there are efficient in terms of manufacturing strong indications that the seat height processing time, safety, training time, and the location of handlebars and and worker productivity, satisfaction footrests do not adequately cater for and job attitudes. the preferences of the users. 19.2.30(105491)
Freivalds, A. The ergonomics of tools. In- International reviews of ergonomics, Vol 1, D.J. Oborne (Ed). Taylor and Francis, London, 1987, pp 4 3 - 7 5 . Tools are as old as the human race, originating as extensions of arms and hands. By increasing the performance of basic tools, the human could progress to more effective food production and eventually to highly skilled industrial operations. A survey is presented of common hand tools and the features of each that produce the optimum interface between the human operator and the tool. Basic ergonomics concepts, such as maximising functional forces, optimising posture and hand position, and minimising the physical stress and resulting physiological strain, are discussed, along with some introductory hand anatomy and musculoskeletal problems resulting from improper tool usage and design. Lastly, an outline of general ergonomics criteria useful in the design of tools is presented. 19.2.31 (105493) Van der Grinten, M. Shovel design and back load in digging trenches. In: Musculoskeletal disorders at work, P. Buckle (Ed). Taylor and Francis, London, 1987, pp 9 6 - 1 0 1 . In an experimental field study, the effect of shovel design on back load during digging trenches in compact sand was studied. Three different designs with modestly modified length and curvature of the handle were compared with a 'standard shovel'. The trunk flexion and the biomechanical
Environment 19.2.33 (105554)
Parsons, K.C. Practical methods for assessing human response to thermal environments. In: New methods in applied ergonomics, J.R. Wilson, E.N. Corlett and I. Manenica (Eds). Taylor and Francis, London, 1987, pp 137-152. The principles and practice of assessing human response to hot, neutral and cold environments are discussed. Despite some gaps in knowledge, general principles can provide a methodology for assessing the effects of the thermal environment on the health, comfort and performance of workers. A practical assessment of an office for thermal comfort is described. Both physical and subjective measures were made and data analysis methods and final recommendations are provided.
System characteristics 19.2.34 (105578)
Gardiner, M.M., and Christie, B. (Eds) Applying cognitive psychology to userinterface design. John Wiley and Sons Ltd, Chichester, 1987, 381 pp. The design of office automation products to be compatible with their human users must take account of the way humans process information. In order to achieve this, it is important that the design environment and the applied research environment communicate effectively. Complementing work done on an
Bainbridge, L. VDT/VDU interfaces for process control. In: New methods in applied ergonomics, J.R. Wilson, E.N. Corlett and I. Manenica (Eds). Taylor and Francis, London, 1987, pp 9 7 - 1 0 5 . Computer-generated displays on Visual Display Units/Terminals raise some interesting new ergonomics problems. The flexibility of the display format gives greater freedom of design, but there are also new limitations, because displays have to be shown on a small surface areas, so only some of the potential data can be seen at one time. In this paper the dimensions to be considered are briefly outlined. 19.2.21 (105393) Frohlich, D.M. On the organisation of form-filling behaviour. InfDesign J, 1986, 5 (1), 43-59. Given the ubiquity of transactional forms it is surprising that so little is known about the dynamics of the formfilling activity itself. This paper reports a detailed observational study of the reading and routeing activities of subjects as they filled in a DHSS postal claim form. The results of this study suggest a number of broad principles which appear to govern the interaction of subjects with the written material of the form. The local application of these principles in the context of a form-filling history can account for idiosyncrasies in form-filling behaviour. This interpretation is consistent with the view that form-fiUers employ a conversational model of form-filling despite the static nature of the paper medium through which it is conducted.
ware system for problem purposes. Software ergonomics discusses issues concerning the adjustment of software systems to their human users. A model for user interfaces has been proposed by IFIP WG 6.5. This model allows a detailed description of several aspects of a user interface by means of four different interface types. These aspects can be analysed independently. The adaptation of a software system to a working environment is described by the so-cailed 'tool-interface'. This interface comprises the users' access to the software tools of the system. A user-adequate command language should implement a high-quality tool interface. Requirements are established to which the design of the tool interface must adhere. Typical problem situations are illustrated by examples gathered while developing a conception of a user interface for the UNIX operating system.
Display and control design 19.2.23 (105439)
Hodes, D., and Akagi, K. Study, development and design of a mouse. In: A cradle for human factors. Proc Human Factors Soc 30th ann meeting, Dayton, Ohiol 29 S e p - 3 Oct, 1986. Human Factors Soc, Santa Monica, Cal, Vol 2, 1986, pp 9 0 0 - 9 0 4 . A series of research studies was conducted to develop design criteria for a general purpose mechanical input device. The design criteria and parameters were established with ergonomics studies which included task analysis, competitive analysis and human-performance testing. By taking a leadership role in the production issues, human factors engineers were successful in having the results of their research implemented into a new design. This report is a case study which offers some insight into methodological and design issues associated with producing an ergonomically designed product.
19.2.22 (105376)
Hoffmann, C., and Vaider, W.
19.2.24 (105440~
Command language ergonomics. In: Foundation for human-computer communication, K. Hopper and I.A. Newman (Eds). North-Holland, Amsterdam, 1986, pp 2 1 8 - 2 3 4 .
Arnaut, L.Y., and Greenstein, J.S. Optimising the touch tablet: The effects of control-display gain and method of cursor control. Human Factors, 1986, 28(6), 7 1 7 - 7 2 6 .
For a broad range of applications, command languages provide very efficient access to the tools of a software system. The complexity of many systems leads, however, to a gap between the functions offered by the system and those tools actually used by its users. The design of command languages has to solve this problem in a way that provides means for user interfaces which allow both efficient and adequate utilisation of the soft-
The purpose of this research was to assess the effects of control-display gain, method of cursor control, and target size on target selection performance with a touch tablet. In addition, an attempt was made to determine a definition of control-display gain that would generalise across different control-display combinations. The results indicated that a relatively low gain (approximately 0"8 to 1"0) resulted in more efficient target selection
performance than did higher or lower gains. An absolute mode of cursor control, in which the cursor appears on the display in a position corresponding to the location of the finger on the touch tablet, resulted in faster selection rates and fewer target entries prior to confirmation than did a relative mode of. cursor control. Selection of large targets was faster and more accurate than selection of small targets. Alternative explanations for performance differences are discussed. 19.2.25 (105448)
Breitmaier, W.A., Waldrop, G.P., and Lazo, J. Human factors engineering analysis of Marine Corps night attack aircraft. In : A cradle for human factors. Proc Human Factors Soc 30th ann meeting, Dayton, Ohio, 29 S e p - 3 Oct, 1986. Human Factors Soc, Santa Monica, Cal, Vol 2, 1986, pp 8 6 1 - 8 6 4 . The US Marine Corps has proposed sensor and display improvements to provide night attack capability for the AV-8B and F/A-18 aircraft. The aircraft enhancements include the addition of a forward looking infrared sensor displayed on a new raster head-up display, night vision goggle compatibility, and a colour multipurpose display. A human factors engineering analysis was performed to identify the human factors impact of the cockpit changes involved. Included in the analysis were a literature review, interviews with pilots, design considerations review, and development of recommendations based on both human factors standards and lessons learned from similar projects. The primary areas researched were : cockpit lighting, colour displays, and night vision sensor utilisation. 19.2.26 (105462)
Richards, R.E., Gilmore, W.E., and Haney, L.N. Human factors guidelines and methodology in the design of a usercomputer interface: A case study. In: A cradle for human factors. Proc Human Factors Soc 30th ann meeting, Dayton, Ohio, 29 S e p - 3 Oct, 1986. Human Factors Soc, Santa Monica, Cal, Vol 2, 1986, pp 1073-1077. In this case study, human factors personnel were requested to participate in a project team of programmers and operations specialists to design a cathode ray tube (CRT) display system for a complex process control application. This presentation describes the process and benefits obtained by incorporating human factors guidelines and methods in system design. Standard human engineering guidelines and techniques were utilised by the project team. In addition, previously published documents and research
Applied Ergonomics
June 1988
159
findings sponsored by the United States Nuclear Regulatory Commission (USNRC) were used. Preliminary tasks involved a review of the draft plant procedures. Then, interviews with operators were conducted to establish the initial information for the displays. These initial requirements were evaluated against existing guidelines and criteria to determine the optimal presentation formats. Detailed steps of the approaches used, design decisions made, and trade-offs that resulted in the final user-acceptable design are discussed. 19.2.27 (105463)
Roscoe, S.N. VTOL control and display design : Principles and methods. In: International reviews of ergonomics, Vol 1, D.J. Oborne (Ed). Taylor and Francis, London, 1987, pp 135-158. This review covers an area of aircraft control and display research leading to the application of a set of ergonomics design principles to the problems of vertical and translational instrument flight. A system approach to design is interwoven with an holistic approach to experimentation. VTOL missions are analysed to reveal deficiencies in conventional instrumentation, to identify information and control requirements, and to configure and simulate a generic VTOL control and display system. Through a sequential programme of experimentation involving fractional-factorial screening designs and centralcomposite response surface mapping, critical dynamic control and display design parameters are optimised.
Workplace and equipment design 19.2.28 (105479)
Chan, W.L., Pethick, A.J., and Graves, R.J. Ergonomic implications in the design of an engine assembly line. In: Contemporary ergonomics 1987, E.D. Megaw (Ed). Taylor and Francis, London, 1987, pp 1 4 0 - 145. An ergonomics study, simulating four tasks on a new assembly line, indicated that their design would result in the target line cycle times not being achieved. Postural analysis also indicated a high potential risk of back pain problems. The proposed reduction in the number of repair loops on the line could increase repair times and had implications for the selection and training of repairmen. An ergonomics redesign of the workstations recommends changes in the workspace layout, the presentation of workpieces and component stock feeding systems which would improve the
160
Applied Ergonomics
June 1988
operator's health, as well as reducing the process cycle times for the tasks.
moment at L5-SI were used as parameters of back load. The results showed that a newly designed shovel, 19.2.29 (105481) characterised by a relatively large Das, B. curvature, is an acceptable alternative An ergonomic approach to designing a to the standard shovel. However, none manufacturing work system. In t J of the test shovels appeared to be I n d u s t Ergonomics, 1987, 1(3), 231 designed in the best possible way for 240. digging tasks in sand with very high This paper highlights the methodology thrusting resistance. that was applied systematically to 19.2.32 (105513) incorporate ergonomics principles and Robertson, S., and Porter, J.M. data to the design of a manufacturing Motorcycle ergonomics: An work system. The manufacturing task exploratory study. In : Contemporary comprised drilling four holes on a ergonomics 1987, E.D. Megaw (Ed). prepared steel plate. The components Taylor and Francis, London, 1987, of the manufacturing work system pp 173 178. included: manufacturing task, powerfeed drill press, jig, fixture and other This paper describes a questionnaire equipment, workplace layout, operator survey of the ergonomics problems of training and (hard) production motorcycles, and a pilot experimental standard and'feedback. The ergonomicstudy of the preferred riding position ally designed manufacturing work for motorcyclists. A high incidence of system proved to be effective and discomfort was evident and there are efficient in terms of manufacturing strong indications that the seat height processing time, safety, training time, and the location of handlebars and and worker productivity, satisfaction footrests do not adequately cater for and job attitudes. the preferences of the users. 19.2.30(105491)
Freivalds, A. The ergonomics of tools. In- International reviews of ergonomics, Vol 1, D.J. Oborne (Ed). Taylor and Francis, London, 1987, pp 4 3 - 7 5 . Tools are as old as the human race, originating as extensions of arms and hands. By increasing the performance of basic tools, the human could progress to more effective food production and eventually to highly skilled industrial operations. A survey is presented of common hand tools and the features of each that produce the optimum interface between the human operator and the tool. Basic ergonomics concepts, such as maximising functional forces, optimising posture and hand position, and minimising the physical stress and resulting physiological strain, are discussed, along with some introductory hand anatomy and musculoskeletal problems resulting from improper tool usage and design. Lastly, an outline of general ergonomics criteria useful in the design of tools is presented. 19.2.31 (105493) Van der Grinten, M. Shovel design and back load in digging trenches. In: Musculoskeletal disorders at work, P. Buckle (Ed). Taylor and Francis, London, 1987, pp 9 6 - 1 0 1 . In an experimental field study, the effect of shovel design on back load during digging trenches in compact sand was studied. Three different designs with modestly modified length and curvature of the handle were compared with a 'standard shovel'. The trunk flexion and the biomechanical
Environment 19.2.33 (105554)
Parsons, K.C. Practical methods for assessing human response to thermal environments. In: New methods in applied ergonomics, J.R. Wilson, E.N. Corlett and I. Manenica (Eds). Taylor and Francis, London, 1987, pp 137-152. The principles and practice of assessing human response to hot, neutral and cold environments are discussed. Despite some gaps in knowledge, general principles can provide a methodology for assessing the effects of the thermal environment on the health, comfort and performance of workers. A practical assessment of an office for thermal comfort is described. Both physical and subjective measures were made and data analysis methods and final recommendations are provided.
System characteristics 19.2.34 (105578)
Gardiner, M.M., and Christie, B. (Eds) Applying cognitive psychology to userinterface design. John Wiley and Sons Ltd, Chichester, 1987, 381 pp. The design of office automation products to be compatible with their human users must take account of the way humans process information. In order to achieve this, it is important that the design environment and the applied research environment communicate effectively. Complementing work done on an