Comparing selection mechanisms for gaze input techniques in head-mounted displays

Abstract

Head movements are a common input modality on VR/AR headsets. However, although they enable users to control a cursor, they lack an integrated method to trigger actions. Many approaches exist to fill this gap: dedicated "clickers", on-device buttons, mid-air gestures, dwell, speech and new input techniques based on matching head motions to those of visually presented targets. These proposals are diverse and there is a current lack of empirical data on the performance of, experience of, and preference for these different techniques. This hampers the ability of designers to select appropriate input techniques to deploy. We conduct two studies that address this problem. A Fitts' Law study compares five traditional selection techniques and concludes that clicker (hands-on) and dwell (hands-free) provide optimal combinations of precision, speed and physical load. A follow-up study compares clicker and dwell to a motion matching implementation. While clicker remains fastest and dwell most accurate, motion matching may provide a valuable compromise between these two poles.