[Sigia-l] Re: Eye-tracking systems: is it worth the price?

[Gael Laurans]

The real reference of Andrew Duchowski book is

Duchowski, A.T. (2002). Eye Tracking Methodology: Theory and Practice,
Springer Verlag.

Sorry for the mistake.

Gael Laurans

On 8/10/05, Gael Laurans <glaurans at gmail.com> wrote:
> Hi Eryk,
> 
> You're asking the right question indeed : eye tracking is a very exciting
> technology but one should carefully evaluate if it's really worth the price.
> The cost of eye-tracking lies not only in the cost of the equipment itself
> but also in the effort needed to use it.
> 
> There are a lot of time-consuming technical problems you have to deal with
> and a potentially huge quantity of data being produced. With the same time
> and budget it means you will have less ressources available to carefully
> think, prepare and analyse your tests.
> 
> You also have to expect eye tracking failures with some test participants
> (make-up, iris color, some type of glasses all might be a problem depending
> on your equipment, light in the room is important), which also means you're
> going to need a bigger sample to get meaningful data.
> 
> During the test you also need to calibrate the device and to ask your
> subject to be realtively static. Assuming you're testing software, modern
> systems with a standard accuracy (50 Hz, 1 degree of spatial resolution) do
> not require the subject to be perfectly immobile or to wear an equipment but
> they nonetheless need that the subject's head stays in a limited space. If
> the test lasts one or two hours you might have to ask your subject to sit up
> again and again.
> 
> Then because scrolling and differing paths between users might cause
> problems for the eye tracking software, you are sometimes forced to ask your
> test participants to passively look at your homepage before giving them any
> task. Data collected in this way might not be very relevant to understand
> the attentional behaviour of a real, purpose-oriented users.
> 
> Now, what can you expect from eye-tracking ? Basically it allows you to
> distinguish between navigation elements that have been gazed at (and
> presumably seen and attended to) and those which have not (and presumably
> not been perceived at all). So if nobody is clicking the link that would
> help them find the information they're looking for, eye tracking might tell
> you why (not seeing it at all ? not looking in the right place ? not
> understanding the relevance ?). 
> 
> However it is often the case that you are able to guess that by looking at
> the user's behaviour, by probing for it (even if every psychologist knows
> the limitation of self-report data) or in reference to a well-documented
> phenomenon like banner blindness. In any case, all uses of eye-tracking in
> usability I have seen to date are concerned with very low-level
> interaction.
> 
> Regarding literature, Andrew Duchowski's book Eye Tracking Tool and
> Methodology is highly recommended, comprehensive yet very readable (you can
> skip the more technical chapters if you like).
> 
> If you had to read just one thing, I would recommend this note by the
> belgian company Namahn :
> http://www.namahn.com/resources/documents/note-eyetracking.pdf
> 
> An interesting article from David Richardson and Michael Spivey on the
> website of the former
> http://psychology.stanford.edu/~richardson/docs/EyeTrackingEBBE.pdf
> 
> Eye Tracking in Human-Computer Interaction and Usability Research: Ready to
> Deliver the Promises from Robert Jacobs and Keith Karn is available at
> http://www.cs.tufts.edu/~jacob/papers/ecem.pdf
> 
> The famous Poynter studies : http://www.poynterextra.org/et/i.htm and a
> comment from Jakob Nielsen : http://www.useit.com/alertbox/20000514.html
> 
> An article from UIE on the subject :
> http://www.uie.com/articles/eye_tracking/
> 
> A case study from the german company eye square :
> http://www.eye-square.com/documents/EyeTracking-ResearchApplications.pdf
> 
> Another critical view on eye tracking for usability : Eye Tracking in
> Usability: Is It Worthwile ? by Antti Aaltonen
> (http://www.cs.uta.fi/hci/mulmod/material/etusab.pdf)
> 
> The bottom line : eye tracking is interesting for very well-funded projects
> or as a scientific tool but probably not suited to be routinely used in
> usability tests. Now if you have clients ready to pay for the extra thrill
> in the power point presentation...
> 
> Gael Laurans
>