Noise tolerant selection by gaze-controlled pan and zoom in 3D

COMMENT
1. Comment on Manoj's blog


SUMMARY
This paper presents StarGazer, a 3D interface for gaze-based
interaction and target selection using continuous pan and zoom. One of the goals of the paper is to work with cheap low resolution eye trackers. The authors mention that dwell time has been the common way of identifying gaze based selection. However, they argue that this method is unnatural and significantly reduces the speed of the user. The paper presents and zoom and pan based method to to perform this interaction. The format of StarGazer is generic but the authors have described it in context gaze based typing. They describe a circular keyboard with letters arranged in concentric circles. The zooming process reduces the area under contention and hence reduces noise. To navigate within the zoomed in view the user can use panning. In the beginning of a selection user makes a fast saccadic movement, since the confidence here is low, zoom is not used. Once the gaze settles on a selectable object, the object is panned to the center. If the user continues to focus, the object enters the zoomed area and when it gets sufficeintly close (defined by a plane of activation), it is selected. Audio and visual (color of selected object changes) feedback is given. Studies were conducted to see if the Star Gazer interface was easy to use for novice users. 48 users performed a typing task. The mean error rate for large displays was 5.6%. Another test was conducted to measure the typing speed of the users using this interface. Subjects produced 8.16 words per minute with a mean error rate of 1.23%.


DISCUSSION
Although the paper presents a novel way to interact with gaze, I feel that, as is true with all gaze based interfaces, this will lead to considerable fatigue. The paper does not describe the perception of subjects who used the interface. I would have liked to see some qualitative evaluation in addition to the indepth quantitative one which they have provided.