Influences of dwell time and cursor control on the performance in gaze driven typing

In gaze controlled computer interfaces the dwell time is often used as selection criterion. But this solution comes along with several problems, especially in the temporal domain: Eye movement studies on scene perception could demonstrate that fixations of different durations serve different purposes and should therefore be differentiated. The use of dwell time for selection implies the need to distinguish intentional selections from merely perceptual processes, described as the Midas touch problem. Moreover, the feedback of the actual own eye position has not yet been addressed to systematic studies in the context of usability in gaze based computer interaction. We present research on the usability of a simple eye typing set up. Different dwell time and eye position feedback configurations were tested. Our results indicate that smoothing raw eye position and temporal delays in visual feedback enhance the system's functionality and usability. Best overall performance was obtained with a dwell time of 500 ms.