Color Coding of Control Room Displays: The Psychocartography of Visual Layering Effects

Abstract

Objective: To evaluate which of three color coding methods (monochrome, maximally discriminable, and visual layering) used to code four types of control room display format (bars, tables, trend, mimic) was superior in two classes of task (search, compare). Background: It has recently been shown that color coding of visual layers, as used in cartography, may be used to color code any type of information display, but this has yet to be fully evaluated. Method: Twenty-four people took part in a 2 (task) × 3 (coding method) × 4 (format) wholly repeated measures design. The dependent variables assessed were target location reaction time, error rates, workload, and subjective feedback. Results: Overall, the visual layers coding method produced significantly faster reaction times than did the maximally discriminable and the monochrome methods for both the search and compare tasks. No significant difference in errors was observed between conditions for either task type. Significantly less perceived workload was experienced with the visual layers coding method, which was also rated more highly than the other coding methods on a 14-item visual display quality questionnaire. Conclusion: The visual layers coding method is superior to other color coding methods for control room displays when the method supports the user's task. Application: The visual layers color coding method has wide applicability to the design of all complex information displays utilizing color coding, from the most maplike (e.g., air traffic control) to the most abstract (e.g., abstracted ecological display).