A Usability User Study Concerning Free-Hand Microgesture and Wrist-Worn Sensors

Wrist-worn sensors (microphones, time-of-flight cameras, etc) have gained the attention of Human Computer Interaction (HCI) and body sensor researchers for their potential ability to aid interaction with wearable devices. In this paper, we use wrist-worn sensor modalities to evaluate free-hand microgesture usability. Our goal was to determine which microgestures should be included in a potential universal microgesture language and identify any underlying microgestural usability principles. Through a brief pilot user study recording microgesture task time and user accuracy, we were able to explore trends in common usability aspects. Results of the user study showed that free-hand microgestures, even at small physical and temporal scale, have significant effects on task time and user accuracy. Further analysis through multiple comparisons identified which microgestures produce relatively more accurate and efficient interaction. Physical commonalities between such microgestures prompted theories concerning why certain microgestures produce more efficient results. Based on findings and proposed theories, we give suggestions concerning a universal microgestural language and microgestural application development.