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An effect of contrast on legibility of printed text
research and devices, and on complex large-area devices which are opening up new fields for the application of liquid crystal technology.
11.1.18 (77554)
Institute of Occupational Health, Helsinki, Finland Colours at work. (In Finnish.) Ergonomiatiedote, 1978, No 3, 34 pp. The third issue of the Ergonomics Bulletin of 1978 deals with the significance of colour in worklife. Because of the vast number of uses for colour codes, the practical problems of persons with defective colour vision are many, and they should be taken into consideration when a vocation is being chosen by such people. Good lighting, t h e u s e of different shapes (as well as colour) for safety signs, the position of colour signals, and the marking of content, quality, value, etc, with text, all aid colourblind persons in worklife. The use of colours is connected to their perception, which is affected by their contrast and luminance, the distance from which the coloured objects is viewed, size of the field of vision, hue, and the age of the observer. In work,situations safety colours should be used to indicate danger, firefighting equipment and personal protectors and to attract the attention of workers. Colours can also help to produce glareless illumination.
11.1.19 (77559) Willis, P.J. The use of colour information in raster scan display systems. Displays Technology and Application, Apr 1979, 1.1,47-48. Several frame buffer, raster scan display systems are commercially available. Although most are capable of storing adequate colour information this is seldom utilised in the best application-oriented manner. Three possible ways of interpreting colour data are considered in turn.
products. Certain stereotypes for these shape and colour associations emerged from the study, and the relevance of these findings in relation to the design of safety signs is discussed. 11.1.21 (77576)
Breimer, A.J., Timmers, H., and Van der Veen, K.G. The legibility of televised text. Institute for Perception Research, Eindhoven, Netherlands, Annual Progress Report No 13, 1978, 5 8 6 3 . Legibility of televised text has been assessed in a number of experiments. The main experimental variables were chosen to be the number of characters on the TV screen and the viewing distance. The trade-off between character size and distance between lines of text was investigated separately. The main experimental findings show that performance measures are rather stationary in regions where a definite decrease in ease-of-reading ratings is obtained. Furthermore, indications are obtained that readers made their ease-of-reading rating mainly on the number of characters actually present on the TV screen. 11.1.22 (77579) Timmers, H. An effect of contrast on legibility of printed text. Institute for Perception Research, Eindhoven, Netherlands, Annual Progress Report No 13, 1978, 64-67. An experiment is described in which the effect of decreasing contrast on the legibility of isolated threeqetter words is investigated. Reading performance is measured by the percentages of correct responses and by the corresponding voice-response latencies. Contrast is decreased to 12-5% of the highest level; an increase of foveal latency of about 50 ms is found, parafoveal latency shows a n increase of 150 ms: F o r the foveal and 1o parafoveal presentations hardly any effect of contrast is shown, when it is decreased to about 50%. 11.1.23 (77584)
Reynolds, L. 11.1.20 (77562)
Easterby, R.S., and Hakiel, S.R. Safety labelling of consumer products: Shape and colour code stereotypes in the design of signs.TRC Report No T79-8008; University of Aston, Applied Psychology Department, Birmingham, Report No AP-REP-75, Dec 1977, 49 pp, abstr in: R and D Abstracts. Describes a study investigating whether observers associatespecific shapes and cotonrs with signs used for labelling hazardous household
50
AppliedErgonomics March 1980
Teletext and viewdata - a new challenge for the designer: Information Design Journal, 1979, 1.1, 2 " 1 4 . Teletext and viewdata displays present a strong challenge to the information designer. The monospaced dot matrix characters are relatively crude in their design, and their positioning is determined by a fixed grid. The graphics facility is also somewhat crude. The scope for typographic and spatial Coding of information is therefore v e r y limited. There is, however, the possibility of
using colour as a way of coding information. Seven colours, including white, are available, but they are not of equal brightness and this has important implications for legibility. Bearing in mind the constraints and freedoms offered by this kind of display, ways of presenting text, tables. indexes and graphics of various kinds are discussed
Workplace layout and equ ipment design 11.1.24 (77609) Ivergard, T. Bridge design and reliability. An ergonomic questionnaire study. The Swedish Ship Research Foundation (Stiftelsen Svensk Skeppsforskning), Goteborg, Sweden, Report No 5311 : 13. 1976, 77 pp. The Swedish Ship Research Foundation ~s carrying out a large ergonomics project on reliability in the man-ship system. Within the framework of this project, ERGOLAB is responsible for a number of different parts of it. For example, an introductory literature survey has been carried out (Ivergard, 1974) and also a detailed method and theory study (Istance and Ivergard, 1976). A questionnaire study directed towards captains and pilots has now also been completed, and some o f the results are given in this report. There are two main aims of the questionnaire study: (1) To collect subjective opinions on the design of bridges and navigation equipment from the users and the designers (ie, captains, officers, pilots, producers and nautical experts); (2) To collect information on critical incidents which captains and pilots have been involved in during a certain time period. (The part dealing with this aim will be presented in a special report). 11.1.25 (77638)
Kogi, K. Passenger requirements and ergonomics in public transport. Ergonomics, Jun 1979.22.6,631-639. The basic requirements and comfort parameters of users of public transport are discussed with reference to results of some recent field investigations. The needs for city transport were found to consist of primary service associated with time saving and convenience, informational clarity, physical requirements, and environmental factors. The priorities of such needs were variable according to the purpose of travelling, such as commuting, visiting, shopping, business, and others; and also to the users' occupations. The comfort of
11.1.18 (77554)
Institute of Occupational Health, Helsinki, Finland Colours at work. (In Finnish.) Ergonomiatiedote, 1978, No 3, 34 pp. The third issue of the Ergonomics Bulletin of 1978 deals with the significance of colour in worklife. Because of the vast number of uses for colour codes, the practical problems of persons with defective colour vision are many, and they should be taken into consideration when a vocation is being chosen by such people. Good lighting, t h e u s e of different shapes (as well as colour) for safety signs, the position of colour signals, and the marking of content, quality, value, etc, with text, all aid colourblind persons in worklife. The use of colours is connected to their perception, which is affected by their contrast and luminance, the distance from which the coloured objects is viewed, size of the field of vision, hue, and the age of the observer. In work,situations safety colours should be used to indicate danger, firefighting equipment and personal protectors and to attract the attention of workers. Colours can also help to produce glareless illumination.
11.1.19 (77559) Willis, P.J. The use of colour information in raster scan display systems. Displays Technology and Application, Apr 1979, 1.1,47-48. Several frame buffer, raster scan display systems are commercially available. Although most are capable of storing adequate colour information this is seldom utilised in the best application-oriented manner. Three possible ways of interpreting colour data are considered in turn.
products. Certain stereotypes for these shape and colour associations emerged from the study, and the relevance of these findings in relation to the design of safety signs is discussed. 11.1.21 (77576)
Breimer, A.J., Timmers, H., and Van der Veen, K.G. The legibility of televised text. Institute for Perception Research, Eindhoven, Netherlands, Annual Progress Report No 13, 1978, 5 8 6 3 . Legibility of televised text has been assessed in a number of experiments. The main experimental variables were chosen to be the number of characters on the TV screen and the viewing distance. The trade-off between character size and distance between lines of text was investigated separately. The main experimental findings show that performance measures are rather stationary in regions where a definite decrease in ease-of-reading ratings is obtained. Furthermore, indications are obtained that readers made their ease-of-reading rating mainly on the number of characters actually present on the TV screen. 11.1.22 (77579) Timmers, H. An effect of contrast on legibility of printed text. Institute for Perception Research, Eindhoven, Netherlands, Annual Progress Report No 13, 1978, 64-67. An experiment is described in which the effect of decreasing contrast on the legibility of isolated threeqetter words is investigated. Reading performance is measured by the percentages of correct responses and by the corresponding voice-response latencies. Contrast is decreased to 12-5% of the highest level; an increase of foveal latency of about 50 ms is found, parafoveal latency shows a n increase of 150 ms: F o r the foveal and 1o parafoveal presentations hardly any effect of contrast is shown, when it is decreased to about 50%. 11.1.23 (77584)
Reynolds, L. 11.1.20 (77562)
Easterby, R.S., and Hakiel, S.R. Safety labelling of consumer products: Shape and colour code stereotypes in the design of signs.TRC Report No T79-8008; University of Aston, Applied Psychology Department, Birmingham, Report No AP-REP-75, Dec 1977, 49 pp, abstr in: R and D Abstracts. Describes a study investigating whether observers associatespecific shapes and cotonrs with signs used for labelling hazardous household
50
AppliedErgonomics March 1980
Teletext and viewdata - a new challenge for the designer: Information Design Journal, 1979, 1.1, 2 " 1 4 . Teletext and viewdata displays present a strong challenge to the information designer. The monospaced dot matrix characters are relatively crude in their design, and their positioning is determined by a fixed grid. The graphics facility is also somewhat crude. The scope for typographic and spatial Coding of information is therefore v e r y limited. There is, however, the possibility of
using colour as a way of coding information. Seven colours, including white, are available, but they are not of equal brightness and this has important implications for legibility. Bearing in mind the constraints and freedoms offered by this kind of display, ways of presenting text, tables. indexes and graphics of various kinds are discussed
Workplace layout and equ ipment design 11.1.24 (77609) Ivergard, T. Bridge design and reliability. An ergonomic questionnaire study. The Swedish Ship Research Foundation (Stiftelsen Svensk Skeppsforskning), Goteborg, Sweden, Report No 5311 : 13. 1976, 77 pp. The Swedish Ship Research Foundation ~s carrying out a large ergonomics project on reliability in the man-ship system. Within the framework of this project, ERGOLAB is responsible for a number of different parts of it. For example, an introductory literature survey has been carried out (Ivergard, 1974) and also a detailed method and theory study (Istance and Ivergard, 1976). A questionnaire study directed towards captains and pilots has now also been completed, and some o f the results are given in this report. There are two main aims of the questionnaire study: (1) To collect subjective opinions on the design of bridges and navigation equipment from the users and the designers (ie, captains, officers, pilots, producers and nautical experts); (2) To collect information on critical incidents which captains and pilots have been involved in during a certain time period. (The part dealing with this aim will be presented in a special report). 11.1.25 (77638)
Kogi, K. Passenger requirements and ergonomics in public transport. Ergonomics, Jun 1979.22.6,631-639. The basic requirements and comfort parameters of users of public transport are discussed with reference to results of some recent field investigations. The needs for city transport were found to consist of primary service associated with time saving and convenience, informational clarity, physical requirements, and environmental factors. The priorities of such needs were variable according to the purpose of travelling, such as commuting, visiting, shopping, business, and others; and also to the users' occupations. The comfort of