EyePoint: Practical Pointing and Selection

Using Gaze and Keyboard

Manu Kumar, Andreas Paepcke, Terry Winograd

Stanford University, HCI Group 353 Serra Mall, Stanford, CA 94305-9035 {sneaker, paepcke, winograd}@cs.stanford.edu

Comments:

Drew’s Blog

Manoj’s Blog

Summary:

The article presents EyePoint which is a combination of gaze based pointing and keyboard triggered selection. The goal is to develop a simple system which is accurate and fast enough to be a viable alternative to traditional devices such as the mouse. The motivation for the project was to use gaze information to augment traditional input devices, and not serve as a substitute. The visual modality was seen as an input channel, where its use for motor control would be directly at odds with the users natural inclination. This is best illustrated by traditional dwell based systems, which by their very nature have lacked performance rendering them as non viable alternatives.

In the development of EyePoint, research began exploring how users use the mouse for pointing. It was universally seen that the mouse was the preferred method for all object manipulation tasks. Furthermore, for any gaze based system to be viable it would have to be able to execute all the clicking actions such as single, double, right, over, etc. In contrast to deliberate motor actions such as mouse and keyboard input which need no disambiguation. Eye movements need filtering to remove micro and involuntary scads to avoid the midas touch effect. Current gaze based systems suffer from a variety of intrusive functional byproducts undermining their viability.

EyePoint, tries to overcome this by employing a two step progressive refinement procedure in order to compensate for the inaccuracy of eye gaze trackers. The user looks at the desired target and holds down the appropriate hot key for the desired click action. The area being looked at is zoomed the user looks again and releases the hot key to execute the action. Drag is a two step process, where the destination is selected with another hot key. To abort an action the user simply looks outside the zoom area. An interesting refinement is the projection of a focussing grid on the zoomed window to stabilize gaze.

The system is based on four principles:

1. Not slaving any action directly to eye movements.

2. Using zooming to overcome accuracy problems.

3. Fixation and smoothing algorithm.

4. Efficient activation mechanism.

Refinements:

1. Ensuring that the zoom window is bound by the limits of the screen.

2. An animated zoom the reduce secondary saccades.

3. A focussing grid overlay to reduce jitter.

4. A current gaze feedback marker was tested and seen to be distracting.

Evaluation:

20 participants. Three variables: Focus points. Gaze marker. without focus points

1. 10 - 15 min training phase

2. Web Study navigate through 30 pages.

Subjects thought speeds were comparable.

3. Pointing only task to click on the red balloon.

Subjects felt the mouse was faster and more accurate.

4. Mixed typing and pointing with a mouse only measuring the time to point not type.

Subjects liked the reduction in hand movement, but preferred the accuracy of the mouse

Results:

Web Study:

EyePoint with focus marker was 20% slower than the mouse.

EyePint with focus markers was 10%, without was 13% greater error than the mouse.

Balloon Study:

Not a great deal of difference in speed here.

10x the error of the mouse.

Mixed Study:

Again not much difference in times.

20x the error of the mouse.

Discussion:

EyePoint is a well thought out use of gaze controlled pointing. An improvement on previous overloaded approaches. This system maximizes the modalities natural attributes without overburdening them.

However, the traditional mouse uses a single button for several actions single double, drag. EyePoint replaces this with multiple buttons which surely is less economic. It may have been better to use a single hot key similar in function to the traditional model. This brings up the question of ease of use for disabled users.

In the conclusion the data gathered for test three is reinterpreted more favorably by making assumptions. Surely it would be simpler to repeat test three with Eye point to get a direct comparison.