The real value of eye-tracking for UX evaluation?

I’ve been thinking a lot recently about the actual value that eye tracking brings to a UX evaluation. Maybe it’s because i’m mac-bound and to get any kind of eye tracking setup in place I either have to write it myself or venture over to the dark side and get me a windows box. But more and more, i’m starting to question the actual tangible value to a customer other than being a sexy slide in an evaluation presentation.

We all know the drawbacks with eye-tracking. Software is notoriously shaky, results can vary from machine to machine, and of course not all users can actually be tracked. I think i read somewhere that a 20% dropoff is usual, if not the expected norm. I’d back that up, and we often find a much higher dropoff too.

The problem i have is that eye tracking on its own doesn’t measure interaction. All it can help us with is gauging the users visual perception of an interface. Of course thats handy but perception is not the same as actually absorbing that information and acting on it. For that you can’t beat observed testing or capturing interaction using something like silverback or one of the many other tools out there.

Its a shame because clients absolutely love the idea of eye tracking in a kind of bladerunner-esque futuristic context, but they need to be instructed on the inherent shortfalls in the data. We’re looking into more intelligent User evaluation using a heady mixture of data gathering and more traditional routes, hopefully we’ll be able to post about that in the not too distant future.