Investigation Of Smartwatch Touch Behavior With Different Postures

This paper investigates smartwatch touch behaviors of users with different hand postures by conducting a laboratory experiment with 12 participants and analyzing their tap events on a smartwatch with four postures: the no-support (NS) posture, thumb support (TS) posture, index-finger-support (IS) posture, and thumb-and-middle-finger-support (TMS) posture. The participants' movement time and the error rate of the tapping tasks were measured for each posture and for two target positions (edge and center) and three target sizes (large, medium, and small). The results indicate much faster response times for the small, center targets for the TS and TMS postures compared with the NS posture. Based on this result, this paper proposes five design guidelines for arranging touch targets on a smartwatch touchscreen based on four postures.