Eyes and Keys: An Evaluation of Click Alternatives Combining Gaze and Keyboard

With eye gaze tracking technology entering the consumer market, there is an increased interest in using it as an input device, similar to the mouse. This holds promise for situations where a typical desk space is not available. While gaze seems natural for pointing, it is inherently inaccurate, which makes the design of fast and accurate methods for clicking targets (“click alternatives”) difficult. We investigate click alternatives that combine gaze with a standard keyboard (“gaze & key click alternatives”) to achieve an experience where the user's hands can remain on the keyboard all the time. We propose three novel click alternatives (“Letter Assignment”, “Offset Menu” and “Ray Selection”) and present an experiment that compares them with a naive gaze pointing approach (“Gaze & Click”) and the mouse. The experiment uses a randomized, realistic click task in a web browser to collect data about click times and click accuracy, as well as asking users for their preference. Our results indicate that eye gaze tracking is currently too inaccurate for the Gaze & Click approach to work reliably. While Letter Assignment and Offset Menu were usable and a large improvement, they were still significantly slower and less accurate than the mouse.