| This study examined the readability of visual display terminals (VDTs) using 3 background luminance levels (light, medium, and dark), two chromaticities (grey on grey, and green on yellow), and 6 luminance contrast levels (0.05, 0.10, 0.15, 0.20, 0.25, and 0.30). Participants (N = 16) found target words ('square', 'circle', or 'triangle') embedded in the text excerpts that were placed on top of the backgrounds. They responded by selecting the corresponding shape located at the bottom of the screen. In general, the greater the luminance contrast level, the faster the search time for both chromaticities and all background luminance levels. The medium-luminance level background/green text on yellow background condition and the dark-luminance/green text on yellow background condition had more stability than any other conditions. Finally, search times did not correlate with participants' preference ratings of the different stimulus combinations. Designers should keep this in mind when designing software and web pages. |
