Effects of leading-display with double-line on user's comprehension and visual fatigue

[[abstract]]This study examined the factors（position, speed, and double-lined distance） affecting viewers’ comprehension and visual fatigue pertaining to the reading of double-lined dynamic information on an LCD screen. A three-way factorial-design experiment（4 x 3 x 2）using different positions, speed combinations of in-line/out-line, and distances between the up-line and below-line as independent variables was conducted to test the comprehension and visual fatigue associated with reading information on a leading display. The results of this study were as the follows:（1）normally, double-lined dynamic information positioned on the bottom of the TV screen was better than that on the left side of the TV screen.（2）There were no differences among the distances of 0.5, 1.25, and 2 cm between the up-line and below-line.（3）There were differences on account of the various speed combinations. The double-lined speed combinations with 200cpm/85cpm（up-line/below-line）, 85cpm/200cpm, and 85cpm/85cpm were better than the speed combination with 200cpm/200cpm.（4）The longer break may improve the reading comprehension. These results could be used as a reference for websites and TV screen designers for identifying the appropriate levels of displaying leading-display