Kumar, et al. Paper
Design of the system
EyePoint's design incorporates three principles:
1. They do not want to "overload the visual channel for pointing," i.e. don't map interaction directly to eye movement.
2. They aim to increase selection accuracy by including zooming/magnification in such a way that it enhances accuracy but does not inhibit performance. The solution to this is to magnify a square around the gaze area and overlay a grid of orange dots, called "focus points," to enhance fine selection. The magnification avoids distortion of the interface that some techniques, such as fish-eye magnification, introduce. The magnified area is partially transparent as well, to avoid obscuring the interface, as some zooming techniques do.
3. They want to reduce jitter, which they do with "fixation detection and [a] smoothing algorithm."
4. The selection method must be "fluid" and simple in order to make fast selections while maintaining usability by both disabled and normal functioning people. The solution to this is to perform selections with some "hotkeys" (corresponding to click, double click, right click, mouse over, start click-and-drag, and end click-and-drag) on a standard keyboard. The thought is that pressing keys is faster and better than dwell and zooming selection methods.
This system uses a Tobii 1750 eye tracking system.
Usage of the EyePoint software
1. The user looks at the target on the screen.
2. The user presses down one of the hotkeys (click, double click, right click, mouse over, start click-and-drag, and end click-and-drag)
3. A square around the estimated gaze point is magnified in the manner described above.
4. The user looks at the target in the magnified area (this helps enhance the selection)
5. The user releases the hotkey
6. The action of the hotkey is performed
The researchers think that this system can equally be used by able-bodied and disabled users. They propose changing the hotkeys to some other input device depending on the situations of the users. No testing was done in this area, however.
User Study and evaluation
A user study was conducted with 20 normal, able-bodied, participants who were very experienced computer users.
A quantitative evaluation was performed which had the users perform specific tasks, including navigating through web pages and clicking targets. Data including timing and error rates were collected. The tasks were varied to account for any learning curves.
A qualitative evaluation was also performed using a questionnaire to get users opinions of the EyePoint system compared to a standard mouse input.
Results
Web browsing:
The "focus points" did not help with timing or accuracy.
The average time to click a target with EyePoint was about 400 ms slower than a mouse.
The mouse had a lower error rate by about 10% in the normal EyePoint tests.
User's were divided on which system they thought was faster and easier to use (mouse or EyePoint).
75% of the users said they might choose EyePoint in certain situations.
Most users preferred the focus points.
Target selection:
EyePoint is only marginally slower than the mouse for selection.
EyePoint has much higher error rates than the mouse.
Users generally preferred EyePoint for its ease of use despite its lower performance.
Analysis
It was found that EyePoint is similar in speed to the mouse. The error rates for EyePoint vary from user to user. The study participants preferred EyePoint to the mouse.
The researchers conclude that it is possible and practical for an eye tracking system to be used by the common computer user in place of the mouse.
Watch the video if you want:
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I like this eye tracking system the best of the papers we have read so far this semester. I have thought of using eye tracking to augment the mouse in some way, which would mean a system is mostly mouse-based with some eye help. This system is the opposite. It is a an eye-based system with some hand click help. This is pretty cool, and the speed and accuracy results look a lot better than some of the other work we looked at.
I am most intrigued by the magnification solution to enhance accuracy and reduce error by introducing a second focusing saccade at the cost of speed. I do think emphasizing accuracy over speed was a good move by Kumar, et al. since the mouse is already pretty darn fast and the time to actually focus on a target doesn't seem that it could be any faster than the mouse, at least for experienced computer users.
The EyePoint system might increase selection speed for computer novices that might not be used to using a mouse and therefore use it slower than us experienced users. After all, not all people are experience computer users, but nearly all people can see.
3 comments of glory:
It is pretty hard to fixate on a position. The zoom in idea pretty much helps in solving this.Focusing on accuracy was a nice idea. but it was not good either. The users had a positive feedback about the eyepoint though.
I liked this paper. It was more thorough than the other papers we've read. However, I would like to see them fix the problem with the glasses.. for obvious reasons....
The use of the grid background would help fixation, but I am not sure about the increase in the number of hot keys.
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