VIDEO DISPLAY LUMINANCE AND HUMAN PERFORMANCE: THE EFFECTS OF POLARITY, CONTRAST, AND ABSOLUTE LUMINANCE ON VISUAL SEARCH (FACTORS, ENGINEERING, ERGONOMICS)

Two experiments were conducted to examine the effects of video display contrast, image polarity, and absolute luminance on visual search preformance and perference judgements. In a trial, subjects were presented with a target word which they searched for in a subsequent display containing an array of 10 words. Search times, search accuracy, and preference ratings were measured for each factorial combination of the three luminance factors.;Results of the two experiments indicated the following. First, search times leveled off with a display contrast of 4:1 or more. Second, low luminance displays generally led to slower search times than high luminance displays (where high luminance = 10 x low luminance). Third, the low luminance performance decrement was greatest in the low contrast (2:1, 4:1) conditions. Fourth, there were no performance differences found as a function of image polarity. Finally, preference judgements generally agreed with performance measures. The interpretation and implications of these findings were discussed.