Stroke width, illumination level, and figure-ground contrast in numeral visibility.

Two levels each of three numeral visibility variables (stroke width to height ratios of 1:4 and 1:16; illumination level of 0.5 foot-candles and 500 foot-candles; mode of figure-ground contrast-black numbers on white background and the reverse) were studied in a 2 X 2 X 2 analysis of variance, using 40 Ss who provided 5 replications of each possible condition. Of the main effects, only illumination level showed a significant effect on visibility. Stroke width interacted significantly with both illumination level and mode of figure-ground contrast, but the latter two variables did not interact. The interaction of all three variables was also significant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)