Booyah Jared and spot on, of course.
marianne mswe...@speakeasy.net -----Original Message----- From: discuss-boun...@lists.interactiondesigners.com [mailto:discuss-boun...@lists.interactiondesigners.com] On Behalf Of Jared Spool Sent: Friday, August 14, 2009 11:24 AM To: Kristen; Joshua Porter; IxDA Subject: Re: [IxDA Discuss] Eye-Tracker software/hardware recommendations On Aug 14, 2009, at 7:48 AM, Joshua Porter wrote: > Interesting take from Google on their use of eye trackers: > > "In addition to search research, we also use eye-tracking to study the > usability of other products, such as Google News and Image Search. For > these products, eye-tracking helps us answer questions, such as "Is > the 'Top Stories' link discoverable on the left of the Google News > page?" or "How do the users typically scan the image results - in > rows, in columns or in some other way?" > > Eye-tracking gives us valuable information about our users' focus of > attention - information that would be very hard to come by any other > way and that we can use to improve the design of our products. > However, in our ongoing quest to make our products more useful, > usable, and enjoyable, we always complement our eye-tracking studies > with other methods, such as interviews, field studies and live > experiments." > >> More here: >> http://googleblog.blogspot.com/2009/02/eye-tracking-studies-more-than >> -meets.html Ok, may this warrants a more serious response. The problem with Google & everyone else's use of eye tracking is that it requires a leap of faith from observation to inference. We can see the observation clearly and most of the time, we can agree on them. An observation is that the user's gaze was recorded on a specific x/y coordinate for a specific time period. Another observation might be that the device didn't record any gaze fixations on a different x/y coordinate. We might also observe that the first x/y coordinate matches up with a link to a news story. The second x/y coordinate matches up with an advertisement. So, we could conclude that the fixation of the user was on the news because they were interested in it. And that they didn't look at the ad because they weren't interested. But that conclusion could be very flawed. Assuming we can account for any calibration errors in the device (where the x/y coordinates didn't actually match the news link or ad -- a frequent occurrence in state- of-the-art eye tracking systems), we still don't know the brain activity behind the gaze fixations. Maybe they stared at the news link because they were completely baffled by the headline? Maybe they didn't realize it was a news headline and thought it was something else? Maybe they actually saw the ad in a quick, transitive glance that was too fast for the eye tracker to pick up? Maybe they registered the ad out of there peripheral vision, beyond that of the foveal focus region? (Many eye trackers won't show an experienced user's eyes moving to scroll bar even though they move their mouse there to scroll. It seems they acquire the scroll bar with peripheral vision, keeping their focus on the items of interest on the screen.) Jumping too quickly from observation to inference is the #1 cause of design problems. We assume things without eliminating other possibilities, make assumptions, and run with them. Spending a little more time to test our inferences, to ensure we've properly qualified them and eliminated alternative explanations can save a lot of energy and downstream problems. (I've written about this in an article called "The Road to Recommendation": http://www.uie.com/events/roadshow/articles/recommendation/) So, here's the problem with eye trackers: Every inference must be tested without the eye tracker. As the folks from Google say: > we always complement our eye-tracking studies with other methods, such > as interviews, field studies and live experiments. Fact is, had they started with the other methods, they wouldn't have discovered anything new in the eye tracker. And the other methods are cheaper, more efficient, and more beneficial. There is one advantage to eye tracking hardware. On a recent visit to the Googleplex, I asked about their usage their and this observation/ inference problem. They agreed with me, but told me about the "real" reason they use the devices. It turns out, the engineers and developers are more likely to attend usability tests when the eye tracker is in use. In the few labs they have that aren't outfitted with the devices, the engineers and developers rarely attend. They line up to watch eye tracking tests. For that purpose, the device may have some value. But so does good chinese food. I've found that a quality catering job is much more cost effective than mucking with the toys. (At Google, that might not work so well, since they have four-star chefs in their cafeteria -- hard to top that with catering.) That's my more serious response. It pisses off eye-tracking aficionados world-wide. I'm good with that. Jared Jared M. Spool User Interface Engineering 510 Turnpike St., Suite 102, North Andover, MA 01845 e: jsp...@uie.com p: +1 978 327 5561 http://uie.com Blog: http://uie.com/brainsparks Twitter: @jmspool ________________________________________________________________ Welcome to the Interaction Design Association (IxDA)! 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