Evaluation of HeadTurn: An Interaction Technique Using the Gaze and Head Turns.

Smart glasses equipped with eye tracking technology could be utilized to develop natural interaction techniques. They could be used to conveniently interact with an electronic appliance in the environment from a distance. We describe a technique, HeadTurn, that allows a user to look at a device and then control it by turning the head to the left or right. We evaluated HeadTurn using an interface that linked head turning to increasing or decreasing of a number shown on a display. The task was to adjust then number to a given value. We studied the optimal rate at which number should change once the angle of head turn exceed a predefined threshold. We varied the rate of change of the number (217, 290, and 435ms per change) and the feedback (visual, haptic+visual). In the haptic condition, a 20 millisecond vibration was given through vibrating eye glass frame with each number change. Participants completed number selections faster with shorter intervals but also overshot the target more often. Seven out of 12 participants preferred the middle number changing speed (i.e., 290 ms). There were no statistically significant differences in task completion times. The optimal change rate of the numbers seems to be a compromise between faster selection and overshooting. Haptic feedback made the interaction slightly faster but the difference was not significant. The participants rated their experience with the technique as positive in general.