The effect of font size, age and lighting environment on Chinese character legibility

The design of human-computer interface is important and complex. Concerning the Chinese character legibility, three elementary factors are included in this study, namely, age, lighting environment, and font size. 176 subjects divided into three different age groups (19∼35, 35∼55, above 55) participated in the experiment of recognizing four font sizes (6, 9, 12, 24) in three different lighting environments (300 lx, 100 lx, 0 lx), resulting in 21760 data samples. The analysis of the results shows that: 1) Information-transfer bite-rate B is efficient to evaluate Chinese character legibility. 2) Font size 24 is the best for Chinese character legibility, and size 12 and 9 are acceptable, while size 6 is not suitable. 3) The 100 lx typical bedroom environment and 0 lx dark environment are better than 300 lx typical office environment for Chinese character legibility. 4) The fact that age is a significant factor in all the three lighting environments is manifested by B. B of the younger is about 1∼1.2 times of the middle-aged and about 1.1∼1.8 times of the senile. 5) No significant correlations are found among the size, age and lighting environments. We hope that the results of our study may provide references for human-computer interface design to some extent.