Wednesday, February 20, 2008

Inspiration: StarGazer (Skovsgaard et al, 2008)

A major area of research for the COGAIN network is to enable communication for the disabled. The Innovative Communications group at IT University of Copenhagen continuously work on making gaze-based interaction technology more accessible, especially in the field of assistive technology.

The ability to enter text into the system is crucial for communication, without hands or speech this is somewhat problematic. The StartGazer software aims at solving this by introducing a novel 3D approach to text entry. In December I had the opportunity to visit ITU and try the StarGazer (among other things) myself, it is astonishingly easy to use. Within just a minute I was typing with my eyes. Rather than describing what it looks like, see the video below.
The associated paper is to be presented at the ETRA08 conference in March.

This introduces an important solution to the problem of eye tracker inaccuracy namely zooming interfaces. Fixating on a specific region of the screen will display an enlarged version of this area where objects can be earlier discriminated and selected.

The eyes are incredibly fast but from the perspective of eye trackers not really precise. This is due to the physiology properties of our visual system, in specific the foveal region of the eye. This retinal area produces the sharp detailed region of our visual field which in practice covers about the size of a thumbnail on an armslenght distance. To bring another area into focus a saccade will take place which moves the pupil, thus our gaze, this is what is registered by the eye tracker. Hence the discrimination of most eye trackers are in the 0.5-1 degree (in theory that is)

A feasible solution to deal with this limitation in accuracy is to use the display space dynamically and zoom into the areas of interest upon glancing. The zooming interaction style solves some of the issues with inaccuracy and jitter of the eye trackers but in addition it has to be carefully balanced so that it still provides a quick and responsive interface.

However, the to me the novelty in the StarGazer is the notion of traveling through a 3D space, the sensation of movement really catches ones attention and streamlines the interaction. Since text entry is really linear character by character, flying though space by navigating to character after character is a suitable interaction style. Since the interaction is nowhere near the speed of two hand keyboard entry the employment of linguistic probabilities algorithms such as those found in cellphones will be very beneficial (ie. type two or three letters and the most likely words will display in a list) Overall, I find the spatial arrangement of gaze interfaces to be a somewhat unexplored area. Our eyes are made to navigate in a three dimensional world while the traditional desktop interfaces mainly contains a flat 2D view. This is something I intend to investigate further.

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