Display Format and Highlighting Validity Effects on Search Performance Using Complex Visual Displays

Research examining display format and highlight validity (Tullis, 1984; Fisher & Tan, 1989) have shown that these factors affect visual display search; however, these studies have been conducted on small, artificial alphanumeric displays. The present study manipulated these variables, applying them to realistic, complex Space Shuttle displays. A 2 (display type: Orbit Maneuver Execute, Relative Navigation) × 2 (display format: current, reformatted [following human-computer interface design principles]) × 3 (highlighting validity: valid, invalid, no-highlight) within-subjects analysis of variance found significant main effects of these variables on search time and a significant format by highlight interaction. Search through the current, poorly-formatted displays benefitted from valid application of highlight, and showed no cost of invalid highlight. Reformatted displays demonstrated neither reliable cost nor benefit of highlight application. Significant correlations were found between observed search times and search times predicted by Tullis' Display Analysis Program (1986): the relationship was highest with non-highlighted displays and was less predictive with valid and invalid highlight applications. Issues discussed include the enhancement of search through format and highlighting, and the necessity to consider several factors when predicting search performance.