- Email: [email protected]
Aspects of indexing on Prestel
traffic controllers. Human Factors, Oct 1980, 2 2 . 5 , 5 6 9 - 5 8 0 . This paper sets out the basic philosophy of a developing program of computer-aiding concepts for the controller's decision-making. A brief review is given of early work on the computer-assisted approach sequencing (CAAS) concept for a major airport, and the main topic is the interactive conflict resolution (ICR) concept for assisting the en route controller in conflict detection and resolution. ICR is a predictive aid used interactively by the controller; the concept is described in detail. A real-time simulation experiment is reported, in which each of three pairs of controllers acted as an executive/support team in handling traffic samples in a busy sector. Objective records and subjective data suggest the effectiveness and acceptability of ICR. Further research on the controller's activity within, and attitudes towards, computer-based tasks is outlined.
Information processing and transmission by man
13.1.6 (80566)
Megaw, E.D., Bellamy, L., and Powell, J. A methodology to improve inspection performance. In: Ergonomics in Action - From Theory to Practice, Proceedings of the Joint IEA/NES Conference, Oslo, 2 0 - 2 2 Aug 1980, 6 pp, This paper outlines an overall approach to improving industrial visual inspection performance as an alternative to two contrasting approaches that have previously been described in the literature. One of these makes use of a checklist which effectively summarises all those factors which might influence inspector accuracy. While such checklists provide a means of documenting the literature available on the various factors, they do not encourage the adoption of a coherent approach. In addition the practical significances of many of the factors have not been assessed. Typically one can cite the possible effects of time-on-task factor; despite the vast amount of literature concerned with the vigilance decrement, there still exists no conclusive evidence that such a decrement occurs in practical inspection tasks. This is not surprising as anyone who has observed inspectors at work will have noticed the high frequency with which rest pauses are normally taken. The other approach found in the literature is based on developing models that allow one to predict the effects of changing some of the inspection parameters. It is not unfair to say that these models are grossly oversimplified not only in their underlying assumptions but also in the range of parameters which they can accommodate. The benefits arising
66
Applied Ergonomics
from the application of such models have rarely, if ever, been demonstrated in an industrial setting. We therefore have a situation where the checklist approach is too vague and where the modelling approach is too constrained and where both are impracticable. What follows is an attempt to bridge these two approaches by developing a methodology which allows the ergonomist to consider a wide range of factors and, at the same time, to select and evaluate solutions which might not be the optimum, but at least are likely to be cost effective. The methodology must be sufficiently robust to be applicable in the context of the constraints which are met when investigating on-going inspection methods and performance in large competitive companies. For example, one of the first constraints to be encountered is that quality control training departments have a very low priority in most companies.
13.1.7 (80581) Cox, A.C. A comparison of three code schemes for supplementary telephone services. Post Office Research Centre, Martlesham Heath, Ipswich, Post Office Telecommunications Research Department, Report No 802, 1980, 32 pp. This report describes an experiment which was carried out by the PO as part of a collaborative project with a number of other administrations under the auspices of the CCITT. The aim of the project was to compare the three supplementary service code schemes currently under consideration by CCITT Study Group II and to obtain information on customer difficulties with control procedures. The results of the experiment did not provide strong support for any particular code scheme although there was evidence that certain elements within the code schemes caused a disproportionate amount of difficulty to customers. The results described in this report will be collated with those obtained by other administrations and presented to the CCITT by the Study Group Rapporteur. The PO is currently using the CEPT code scheme which was one of the schemes included for study in this project. 13.1.8 (80583)
Rosinski, R.R., Chiesi, H., and Debons, A. Effects of amount of visual feedback on typing performance. In: Human Factors: Science for Working and Living, Proceedings of the 24th
March 1982
Annual Meeting of the Human Factors Society, Los Angeles, Oct 1980, Edited by G.E. Corrick ~:[ a!. pp 1!)5 199. Current hardware and software make it unnecessary to provide visual feedback for a typist. There are few data regarding whether visual feedback is necessary. Prior studies are unclear on this question. Some researchers (Long, 1976) suggest that visual feedback is an important component of the typing task. In the present study, typists of various skill levels typed text, computer programs, or numeric data under conditions which allowed 0, 1, 2, 3, 5, 9, 15, 26, 46, or 79 characters to be seen. Analaysis of typing speed, typographical errors, semantic errors, and an analysis of errors with speed as a covariate revealed that amount of feedback did not affect performance. Visual feedback had an effect only on the number of erasures (corrections) made by the typists. 13.1.9 (80590)
Pollard, D., and James, P. Aspects of indexing on Prestel. In: Proceedings of the Ninth International Symposium on Human Factors in Telecommunications, Red Bank, New Jersey, USA, 29 Sep 3 Oct 1980. pp 9 - 15. The recent introduction of Prestel, the British Post Office viewdata service, has posed the problem of how a database of such a potentially large size can be accessed efficiently by inexperienced and experienced users alike. It is of the utmost importance both for initial user reaction and subsequent efficient system usage that error rates and access times be kept to a minimum. This can best be achieved by careful design of the indexing systems based on performance data obtained from a sample of users. The experiments described have investigated some of the fundamental parameters of interest to Prestel index designers. In particular alternative formats and coding methods have been compared. Indexing methods incorporating the findings of these experiments and others should provide users with the basis of an efficient means of accessing the large databases associated with the system.
Factors affecting perceptual-motor performance in man 13.1.10 (80615)
Pelikanova, J. Preventive medical care as one of the possible ways of ergonomics in highly automated control systems. In:
Information processing and transmission by man
13.1.6 (80566)
Megaw, E.D., Bellamy, L., and Powell, J. A methodology to improve inspection performance. In: Ergonomics in Action - From Theory to Practice, Proceedings of the Joint IEA/NES Conference, Oslo, 2 0 - 2 2 Aug 1980, 6 pp, This paper outlines an overall approach to improving industrial visual inspection performance as an alternative to two contrasting approaches that have previously been described in the literature. One of these makes use of a checklist which effectively summarises all those factors which might influence inspector accuracy. While such checklists provide a means of documenting the literature available on the various factors, they do not encourage the adoption of a coherent approach. In addition the practical significances of many of the factors have not been assessed. Typically one can cite the possible effects of time-on-task factor; despite the vast amount of literature concerned with the vigilance decrement, there still exists no conclusive evidence that such a decrement occurs in practical inspection tasks. This is not surprising as anyone who has observed inspectors at work will have noticed the high frequency with which rest pauses are normally taken. The other approach found in the literature is based on developing models that allow one to predict the effects of changing some of the inspection parameters. It is not unfair to say that these models are grossly oversimplified not only in their underlying assumptions but also in the range of parameters which they can accommodate. The benefits arising
66
Applied Ergonomics
from the application of such models have rarely, if ever, been demonstrated in an industrial setting. We therefore have a situation where the checklist approach is too vague and where the modelling approach is too constrained and where both are impracticable. What follows is an attempt to bridge these two approaches by developing a methodology which allows the ergonomist to consider a wide range of factors and, at the same time, to select and evaluate solutions which might not be the optimum, but at least are likely to be cost effective. The methodology must be sufficiently robust to be applicable in the context of the constraints which are met when investigating on-going inspection methods and performance in large competitive companies. For example, one of the first constraints to be encountered is that quality control training departments have a very low priority in most companies.
13.1.7 (80581) Cox, A.C. A comparison of three code schemes for supplementary telephone services. Post Office Research Centre, Martlesham Heath, Ipswich, Post Office Telecommunications Research Department, Report No 802, 1980, 32 pp. This report describes an experiment which was carried out by the PO as part of a collaborative project with a number of other administrations under the auspices of the CCITT. The aim of the project was to compare the three supplementary service code schemes currently under consideration by CCITT Study Group II and to obtain information on customer difficulties with control procedures. The results of the experiment did not provide strong support for any particular code scheme although there was evidence that certain elements within the code schemes caused a disproportionate amount of difficulty to customers. The results described in this report will be collated with those obtained by other administrations and presented to the CCITT by the Study Group Rapporteur. The PO is currently using the CEPT code scheme which was one of the schemes included for study in this project. 13.1.8 (80583)
Rosinski, R.R., Chiesi, H., and Debons, A. Effects of amount of visual feedback on typing performance. In: Human Factors: Science for Working and Living, Proceedings of the 24th
March 1982
Annual Meeting of the Human Factors Society, Los Angeles, Oct 1980, Edited by G.E. Corrick ~:[ a!. pp 1!)5 199. Current hardware and software make it unnecessary to provide visual feedback for a typist. There are few data regarding whether visual feedback is necessary. Prior studies are unclear on this question. Some researchers (Long, 1976) suggest that visual feedback is an important component of the typing task. In the present study, typists of various skill levels typed text, computer programs, or numeric data under conditions which allowed 0, 1, 2, 3, 5, 9, 15, 26, 46, or 79 characters to be seen. Analaysis of typing speed, typographical errors, semantic errors, and an analysis of errors with speed as a covariate revealed that amount of feedback did not affect performance. Visual feedback had an effect only on the number of erasures (corrections) made by the typists. 13.1.9 (80590)
Pollard, D., and James, P. Aspects of indexing on Prestel. In: Proceedings of the Ninth International Symposium on Human Factors in Telecommunications, Red Bank, New Jersey, USA, 29 Sep 3 Oct 1980. pp 9 - 15. The recent introduction of Prestel, the British Post Office viewdata service, has posed the problem of how a database of such a potentially large size can be accessed efficiently by inexperienced and experienced users alike. It is of the utmost importance both for initial user reaction and subsequent efficient system usage that error rates and access times be kept to a minimum. This can best be achieved by careful design of the indexing systems based on performance data obtained from a sample of users. The experiments described have investigated some of the fundamental parameters of interest to Prestel index designers. In particular alternative formats and coding methods have been compared. Indexing methods incorporating the findings of these experiments and others should provide users with the basis of an efficient means of accessing the large databases associated with the system.
Factors affecting perceptual-motor performance in man 13.1.10 (80615)
Pelikanova, J. Preventive medical care as one of the possible ways of ergonomics in highly automated control systems. In: