Effect of the color tablet computer's polarity and character size on legibility

Abstract

This study aimed to explore how different polarities and character sizes on tablet e-readers affect users' legibility and visual fatigue. Following the experimental method, 30 participants were required to search for the target words in pseudo-texts; meanwhile, the experimental data were connected to an exclusive database through the Internet. Thus, the participants' search times, accuracy rates, and visual fatigue levels could be analyzed. As indicated by the analytic result, all the four kinds of character size affected search time. Specifically, the 8-pt target words on a 10.1-inch screen had the slowest search speed. As character size increased to 12 pt, search speed became significantly faster. Besides, the interaction between polarity and character size had a significant effect on the accuracy rate of searched target words. This study showed that as a character size increased, polarity produced a higher accuracy rate, and that negative polarity had a more significant effect than positive polarity. Under positive polarity, 8 pt had the lowest accuracy rate, and 10 pt had the next lowest accuracy rate. However, after the character size was increased to 12 pt or above, the accuracy rate was not promoted. Moreover, a larger character size produced a higher accuracy rate. Therefore, 12 pt and 14 pt got the best performance. As for visual fatigue, a small character size was the main factor. The findings of this study can be used in the design of tablet e-readers. © 2014 Springer International Publishing.