Investigating the Characteristics of Unistroke Gestures using a Mobile Game

Touch gestures are today’s main input method for the interaction with smart phones. In particular, unistroke gestures, which are gestures consisting of one articulated line, are commonly used for text input (touch keyboards) and short cuts referring to functions on mobile devices. This work investigates the user’s accuracy of articulating unistroke touch gestures on mobile devices. Therefore, two studies were conducted which focused on the user’s ability to perceive different variations of unistroke gestures and reproduce them accurately. First, a control study aimed at analyzing the user’s touch accuracy during the articulation of single line and composed line gestures by varying gesture properties like the rotation or angles within the gestures. To analyze the influences of the user’s distraction in his natural environment, a large scale study was conducted which used a mobile game as apparatus. The game was designed in a way that the user was motivated to articulate the given gestures precisely. The game principle was based on the control study procedure of perceiving and reproducing gestures. To gather a great amount of touch samples the game was published on a mobile app store and the samples were collected trough the internet. The analysis of both studies showed that the gestures orientation and the angles within the gestures affected the articulation accuracy in terms of the deviations made by bending, rotating, and varying the shape of the gestures. Furthermore, the gestures articulated in the game study tended to be more error-prone compared to those being articulated in the control study.