Gaze-controlled HCI and the Midas-Touch problem · Gaze-controlled HCI and the Midas-Touch problem...
Transcript of Gaze-controlled HCI and the Midas-Touch problem · Gaze-controlled HCI and the Midas-Touch problem...
Gaze-controlled HCI and the Midas-Touch problem
Hendrik Koesling
Collaborative Research Centre 673 Alignment in Communication
Centre of Excellence 277 Cognitive Interaction Technology
Bielefeld University
Introduction
“Gaze mouse”
Gaze-controlled HCI: Issues …
How to select an action?
How to detect the intention to select an action?
Midas-Touch problem
Distinction between attention for exploration and attention for selection
… and solutions
Volitional action-selection methods
Gaze mouse + manual action selection
Fixating
Blinking
Separate action-selection areas
… and solutions
Volitional action-selection methods
Gaze mouse + manual action selection
Fixating
Blinking
Separate action-selection areas
Research Questions
Efficiency: Is one of the fixation or blinking methods more efficient than the other?
Usability: Do users prefer one method to the other?
Acquisition: How easy are the two methods to learn?
Experimental method
Task
Gaze typing
Participants
20 German native speakers
10 female, 10 male; mean age 24.3 years
Apparatus
LC Technologies EyeGaze eye tracker @ 120 Hz
t
Experimental method
Stimuli & Procedure
Task area
Input control area
Interaction area
German sentences
6-11 words, 55-65 characters
Selection threshold: 300 ms
…
…
+MB
Experimental method
Design
2 blocks (fixation, blinking)
5 trials per block
Balanced for number of characters,sequence of methods & gender
+ Questionnaire
IV: Method, gender, seq. of methods
DV: Error rate, completion time; quest.
Results – Error rate ER
Fewer errors with blinking method
t(19) = 4.187; p < 0.001
Females: t(9) = 2.480; p = 0.038Males: t(9) = 3.279; p < 0.001Females vs. males: not signif.
No gender difference
Blink-fix: t(9) = 2.124; p = 0.063 (trend)Fix-blink: t(9) = 4.351; p < 0.001
Without practice, blinking & fixation equalPractice benefit for blinking method
Results – Completion time CT
Not signif.
No difference in CT between methods
Females: not signif.Males: not signif.Females vs. males: t(9) = 2.232; p < 0.031
Females’ CTs longer than males’Practice benefit for fixation method
Blink-fix: t(9) = 4.507; p < 0.001Fix-blink: not signif.
Results – Practice Usability
Initial improvement through practice
Followed by possible fatigue effects
User ratings
Method easier to get used to?
… less error prone?
… more accurate?
… less tiring?
… more intuitive?
Use gaze-controlled HCI?
Conclusions
Both gaze-contingent selection methods present feasible approaches to solve the Midas-touch problem.
No method can be preferred over the other.
Blinking method produces fewer errors and allows for more accurate selections
Without practice, fixation method may not necessarily be more error-prone. Task completion times in particular for the fixation method benefit from practice.
Thus, after practice, fixation method may be more efficient than blinking method.
Furthermore, fixation method is rated as less tiring and more intuitive – relevant with regard to user-friendliness, user satisfaction and possible long-term effects of novel interaction methods on users.
Conclusions
Blinking method appears to be well suited for applications where only few selections are needed, that does not rely on a “fluent” input stream and does not allow much time for practice.
Possible applications: ticket vending machines, filling in forms in multiple choice style, sending action command to robots.
Fixation method better suited for continuous, long-lasting and rapid interaction with an application. When users are appropriately trained in using the fixation method, they may consider this interaction method an intuitive, user-friendly means of communication with their environment.
Possible applications: virtual keyboards, in particular for users with motor control deficits.
Outlook
Test handicapped participants
Examine practice effects more closely
Evaluate alternative gaze-controlled action-selection methods
…
Thank you!