Digging Unintentional Displacement for One-Handed Thumb Use on Touchscreen-Based Mobile Devices

摘要

There is usually an unaware screen distance between initial contact and final lift-off when users tap on touchscreen-based mobile devices with their fingers, which may affect users' target selection accuracy, gesture performance, etc. In this paper, we summarize such case as unintentional displacement and give its models under both static and dynamic scenarios. We then conducted two user studies to understand unintentional displacement for the widely-adopted one-handed thumb use on touchscreen-based mobile devices under both scenarios respectively. Our findings shed light on the following four questions: 1) what are the factors that affect unintentional displacement; 2) what is the distance range of the displacement; 3) how is the distance varying over time; 4) how are the unintentional points distributed around the initial contact point. These results not only explain certain touch inaccuracy, but also provide important reference for optimization and future design of UI components, gestures, input techniques, etc.