Speed and accuracy of information processing as a function of display coding method, target density, and task type

Fifty-four subjects randomly assigned to six groups in a 2x3x3 experimental paradigm were required to locate, count, and identify designated targets on displays of 40, 80, or 120 lettered, colored, and shaped items. Half of the subjects performed in a single task situation and half performed in a forced time-sharing task situation. Dependent measures were response times, percent correct responses, and rate of information processing (bits/sec). Results indicated significant effects of density and coding method for the location and counting tasks but not for the identification task. Color coding appeared to be the best coding method, followed by letter and shape coding respectively in both task situations. The superiority of color over the other two coding methods for the location and counting tasks was found to be greater in the time-shared task situation than in the single task situation, and this was attributed to color's attention-getting characteristics. It was concluded that attention becomes a critical factor in time-shared task situations. Implications of the findings for display design, as well as suggestions for further research, were stated.