Effects of touchscreen gesture's type and direction on finger-touch input performance and subjective ratings.

This study examined how finger-touch input performance (i.e. task completion time, failure status, and error rate) and subjective ratings (i.e. performance and physical demand) are influenced by touchscreen gestures' type and direction. Twenty participants performed one-touch (i.e. drag and swipe) and two-touch (i.e. pinch and spread) gesture tasks on a tablet, using several major directions (i.e. eight directions for one-touch and four directions for two-touch gestures). The results showed that swipe was approximately 4.5 times faster than drag, but pinch and spread showed no significant difference in task completion time. Dragging and pinching showed more failures or higher error rates compared to swiping and spreading, respectively. One-touch gestures in the horizontal directions were rated to have higher performance and lower physical demand than those in the vertical and diagonal directions. Two-touch gestures in the horizontal directions took the shortest time but caused more failures and higher error rates. Practitioner Summary: This study provides evidence for the effects of touchscreen gestures' type and direction on human performance and subjective ratings, which varied depending on the number of fingers used. Designers should arrange related touchscreen components accordingly, to improve touch-finger input performance and reduce user workload.