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Sources of stress affecting pilot judgement
connector diameter, with similar strength patterns exhibited for tightening and loosening. Higher torque was exerted when the connectors were on the subject's right side. The use of gloves resulted in higher torque in most situations. Connector height and direction of rotation had little effect on torque strength. 21.1.18 (113232) Imrhan, S.N. A comparison of the results of recent studies in wrist-twisting strength. In: Trends in Ergonomics/Human Factors V, F. Aghazadeh (Ed). North-Holland, Amsterdam, 1988, pp 2 3 5 - 2 3 9 , 7 refs. Seven relatively recent studies on wrist-twisting strength have been compared. The studies reveal that, for circular screw-type container lids, wrist-twisting torque depends mainly on the diameter and surface finish of the lids. The diameter and height influences the type of grip used, and hence torque. Knurls and threads on commercial lids have been ineffective for torque generation, except for very large-diameter lids. Enough data does not exist to make strong conclusions concerning relationships between torque and lid height, body posture and different age groups of the population. 21.1.19 (113246)
Oman, P.W., Gomes, C.S., Rains, K., and Morandi, M. Posture and VDU operator satisfaction.
SIGCHIBull, 1989, 20.3, 5 2 - 5 7 , 19 refs. Few studies have looked at how workers adapt their posture, to fit their work environment, and virtually none has compared this adaptation with reports of user satisfaction. This study focused on the relationship between users' size and posture, and the phsyical attributes of VDU workplaces. A survey on VDU operator satisfaction was conducted and compared with results from a controlled study on posture transitions occurring at VDU workplaces. Results demonstrate that workers adapt their posture to fit their work environment, rather than adjust their workstation to permit an optimal posture that may increase productivity. These results support the recommendations for comprehensive worker training on the ergonomics benefits of workstation adjustment and suggest the need for dynamically adjustable workstation components that periodically conform to the worker's posture. 21.1.20 (113321)
James, A. Perceptions of stress in British ambulance personnel. Work and Stress, 1988, 2 . 4 , 3 1 9 326, 12refs.
This paper reports upon an investigative study of stress in the ambulance service. The aims of the research were in part methodological and in part substantive. Methodologically, the study sought to validate as measurable constructs the perceptions of sources of stress reported by ambulance staff in response to questionnaire items. Substantively, it sought to identify these possible sources of stress and to measure the relationship between their perceived importance and such moderating variables as personality charactersitics, length of service, and urban or rural locations of operation and rank. Both aspects of the study are reported. 21.1.21 (113323)
Simmel, E.C., Cerkovnik, M., and McCarthy, J.E. Sources of stress affecting pilot judgement. Aviation, Space & Environ Med, 1989, 60.1, 5 3 - 5 5 , 7 refs. The initial stages of the research on the effects of the over-assessment or under-assessment of the consequences of non-routine events (a potentially important factor in decision-making by pilots) is described. Critical difficulties in the measurement of life stress are discussed and a partial solution is suggested in the form of the Life Events Questionnaire (LEQ), an instrument on which individuals report the nature of stressful events, when they happened, and how much they concern them at the time of testing. The results show that the tendency to over-assess or underassess the consequences of non-routine events is consistent within individuals, but is unaffected by life stress levels on the artificial air traffic control simulation used. Analysis of LEQ results showed that high-stress subjects had much higher chronic than acute stress scores (p < 0-001), although the chronic and acute scores were virtually identical for low-stress subjects.
a readily detectible alphanumeric change; complex events (detection of two aircraft at the same altitude on the same flight path) required considerable information processing for detection. Behaviours following detection of each type of event enabled acquisition of data on short-term memory, decision time and errors, procedural errors and motor movement time. Time to detect aircraft at the same altitude was found to increase significantly over the 2 h as did failures to detect these events. Detection time for the simple type of event showed no evidence of impairment, nor was any impairment found for any of the other task behaviours that were measured. The results are discussed with reference to previous studies which suggest that the extent to which attentional decline impairs complex monitoring performance may be related to the amount of information processing required for event detection.
Information
presentation and communication 21.1.23 (113346)
Kaster, J., and Widdel, H. Interactive colour coding of digital maps on electronic displays. Displays Technol and Applications, 1989, 10.1, 1 2 - 1 6 , 12 refs. An interactive method is used to define parameters of colour codes on CRT displays and the applications of this method given for the design of digital maps on electronic displays. The present approach is based on the concept of the photo-colorimetric space, which offers the opportunity for the formal description of CRT characteristics. An experiment using this method for colouring electronic map displays is described and the results are presented. 21.1.24 (113347)
Dewar, R. 21.1.22 (113329) Effects of high visual taskload on the behaviours involved in complex monitoring. Ergonomics, 1989, 32.1, 2 7 - 3 8 , 12 refs
Criteria for the design and evaluation of traffic sign symbols. In: Traffic Control Devices 1988. Transportation Research Board, Washington, DC, Transportation Research Record 1160, 1988, pp 1 - 6 , 15 refs.
A simulated air traffic control task was used to study the effects of prolonged monitoring on some of the behaviours (complex discriminations, interpretations, decision, memory for actions taken) frequently associated with operational monitoring tasks, but seldom examined in laboratory vigilance studies. Forty-eight subjects performed the monitoring task under relatively high taskload conditions for 2 h. Two types of critical events were employed. Simple events consisted of
Several criteria for traffic sign symbols were examined through a questionnaire survey that allowed determination of the importance, or weighting, that should be assigned to each symbol in the design and evaluation of signs. The survey sample included traffic sign experts (members of national traffic control device committees) and practising traffic engineers from Australia, New Zealand, Canada and the United States. Separate ratings were assembled for symbols in general and for warning,
Thackray, R.I., and Touchstone, R.M.
Applied Ergonomics
March 1990
79
Oman, P.W., Gomes, C.S., Rains, K., and Morandi, M. Posture and VDU operator satisfaction.
SIGCHIBull, 1989, 20.3, 5 2 - 5 7 , 19 refs. Few studies have looked at how workers adapt their posture, to fit their work environment, and virtually none has compared this adaptation with reports of user satisfaction. This study focused on the relationship between users' size and posture, and the phsyical attributes of VDU workplaces. A survey on VDU operator satisfaction was conducted and compared with results from a controlled study on posture transitions occurring at VDU workplaces. Results demonstrate that workers adapt their posture to fit their work environment, rather than adjust their workstation to permit an optimal posture that may increase productivity. These results support the recommendations for comprehensive worker training on the ergonomics benefits of workstation adjustment and suggest the need for dynamically adjustable workstation components that periodically conform to the worker's posture. 21.1.20 (113321)
James, A. Perceptions of stress in British ambulance personnel. Work and Stress, 1988, 2 . 4 , 3 1 9 326, 12refs.
This paper reports upon an investigative study of stress in the ambulance service. The aims of the research were in part methodological and in part substantive. Methodologically, the study sought to validate as measurable constructs the perceptions of sources of stress reported by ambulance staff in response to questionnaire items. Substantively, it sought to identify these possible sources of stress and to measure the relationship between their perceived importance and such moderating variables as personality charactersitics, length of service, and urban or rural locations of operation and rank. Both aspects of the study are reported. 21.1.21 (113323)
Simmel, E.C., Cerkovnik, M., and McCarthy, J.E. Sources of stress affecting pilot judgement. Aviation, Space & Environ Med, 1989, 60.1, 5 3 - 5 5 , 7 refs. The initial stages of the research on the effects of the over-assessment or under-assessment of the consequences of non-routine events (a potentially important factor in decision-making by pilots) is described. Critical difficulties in the measurement of life stress are discussed and a partial solution is suggested in the form of the Life Events Questionnaire (LEQ), an instrument on which individuals report the nature of stressful events, when they happened, and how much they concern them at the time of testing. The results show that the tendency to over-assess or underassess the consequences of non-routine events is consistent within individuals, but is unaffected by life stress levels on the artificial air traffic control simulation used. Analysis of LEQ results showed that high-stress subjects had much higher chronic than acute stress scores (p < 0-001), although the chronic and acute scores were virtually identical for low-stress subjects.
a readily detectible alphanumeric change; complex events (detection of two aircraft at the same altitude on the same flight path) required considerable information processing for detection. Behaviours following detection of each type of event enabled acquisition of data on short-term memory, decision time and errors, procedural errors and motor movement time. Time to detect aircraft at the same altitude was found to increase significantly over the 2 h as did failures to detect these events. Detection time for the simple type of event showed no evidence of impairment, nor was any impairment found for any of the other task behaviours that were measured. The results are discussed with reference to previous studies which suggest that the extent to which attentional decline impairs complex monitoring performance may be related to the amount of information processing required for event detection.
Information
presentation and communication 21.1.23 (113346)
Kaster, J., and Widdel, H. Interactive colour coding of digital maps on electronic displays. Displays Technol and Applications, 1989, 10.1, 1 2 - 1 6 , 12 refs. An interactive method is used to define parameters of colour codes on CRT displays and the applications of this method given for the design of digital maps on electronic displays. The present approach is based on the concept of the photo-colorimetric space, which offers the opportunity for the formal description of CRT characteristics. An experiment using this method for colouring electronic map displays is described and the results are presented. 21.1.24 (113347)
Dewar, R. 21.1.22 (113329) Effects of high visual taskload on the behaviours involved in complex monitoring. Ergonomics, 1989, 32.1, 2 7 - 3 8 , 12 refs
Criteria for the design and evaluation of traffic sign symbols. In: Traffic Control Devices 1988. Transportation Research Board, Washington, DC, Transportation Research Record 1160, 1988, pp 1 - 6 , 15 refs.
A simulated air traffic control task was used to study the effects of prolonged monitoring on some of the behaviours (complex discriminations, interpretations, decision, memory for actions taken) frequently associated with operational monitoring tasks, but seldom examined in laboratory vigilance studies. Forty-eight subjects performed the monitoring task under relatively high taskload conditions for 2 h. Two types of critical events were employed. Simple events consisted of
Several criteria for traffic sign symbols were examined through a questionnaire survey that allowed determination of the importance, or weighting, that should be assigned to each symbol in the design and evaluation of signs. The survey sample included traffic sign experts (members of national traffic control device committees) and practising traffic engineers from Australia, New Zealand, Canada and the United States. Separate ratings were assembled for symbols in general and for warning,
Thackray, R.I., and Touchstone, R.M.
Applied Ergonomics
March 1990
79