1. Speed-accuracy Trade-off in Dwell-based Eye Pointing Tasks at Different Cognitive Levels Xinyong Zhang, Pianpian Xu, Qing Zhang and Hongbin Zha. In Proceedings of the 1st international workshop on pervasive eye tracking & mobile eye-based interaction (PETMEI '11). 2011. ACM, New York, NY, USA, pp37-42.

2. Dwell-based selection Illustration adapted from Leishman SPEED ACCURACY MIDAS TOUCH 3000ms100msTypical Dwell time

3. “The cognitive complexity of target searching is a crucial factor that can affect gaze-based interactions.” Previous research is oversimplified

4. PerceptionControl Search performance is affected by the features, such as color, orientation, shape, size, spatial frequency… Controlled by previous experiences, current needs and future goals A cognitive process that includes: reading, comprehension, judgment, de-cision making and problem solving During gaze-based visual search the eyes play a dual role of perception and control organs

5. Conducted an experiment to explore the effects of different dwell times on human performance under different degrees of complexity (cognitive load).

6. Study Participants: 21 (10 female, 11 male) non-native English speakers. Apparatus: EyeLink II eye tracker (in pupil-only mode and at a sampling rate of 250Hz). repeated measures within-subject design Dwell time: Four dwell time levels: 450, 650, 850 and 1100 ms 3 levels of complexity

7. For non-native English speakers, different lengths of text strings imply different complexities of visual search. Table showing the 3 levels of complexity

8. Visual search interface

9. searching time increased with the increase of cognitive complexity Average eye searching time by combination of task complexity and dwell time.

10. A dwell time of 850ms would be suitable for the targets labeled using a simple word. Error rate by combination of task complexity and dwell time.