Abstract: Few studies investigating the merits of colour coding use displays where a fixed background picture increases the predictability of the number or location of the signals. In this study the effects of type of task, coding and display format on the use of VDU-presented information are examined. Two types of tasks were used: a search task and an identification task. There were three coding conditions: shape, colour and colour/shape coding. Information could be displayed in fixed and free format. In fixed format displays the coded information was presented as measuring points in flow schemes of a crude oil distilling plant. In the free format displays this background picture was not presented.

The results show that the background pattern decreases search performance under all coding conditions. Search with shape coding is inferior to that with colour and colour/shape coding. Identification task performance is slightly better with shape coding. The results suggest, that in the search task the background pattern inhibits efficient scanning of the display.

Keywords: CRT; Coding, color; Coding, shape; Color; Empirical studies; Prototyping; Screen output; VDT/VDU; Visual search

Originally published: Proceedings of the Human Factors Society 28th Annual Meeting, 1984, pp. 331-335

Republished: G. Perlman, G. K. Green, & M. S. Wogalter (Eds.) Human Factors Perspectives on Human-Computer Interaction: Selections from Proceedings of Human Factors and Ergonomics Society Annual Meetings, 1983-1994, Santa Monica, CA: HFES, 1995, pp. 19-23.