4. Results
4.1. Data analysis
A two-way repeated measures analysis of variance (RM-ANOVA) was conducted to compare the effects of the softness of the touchscreen (glass surface vs. elastic surface) and the direct input devices (fingertip vs. stylus with acrylic tip vs. stylus with rubber tip) on user task performance and subjective satisfaction. For analysis of task performance, the two standard deviation rule was employed for the detection of outliers and the individual data points that exceeded the mean±2 SD were deleted and replaced with the mean value. To combine the five dependent variables into a composite measure, a new variable called “subjective satisfaction” was created by computing the mean of all measured variables: perceived feeling of pressing down on the surface, pleasantness, helpfulness, finger fatigue, and degree of elasticity. As finger fatigue addressed a negative aspect of the touch experience, the scores were reverse coded before being combined with the other variables.