On Aug 15, 2009, at 1:27 PM, Nick Gould wrote:
Where I part company, respectfully, with Jared is in his assertion
(made here and elsewhere, forcefully) that ET provides no information
that can't be learned through traditional means. That's just
factually false. Eye tracking tells you where users look on the page;
where attention clusters and the paths they take as they explore.
Users can't tell you this information. And when the question you are
asking is "do they see X?" the eye tracker can give you your answer.
It's that simple. We, and our clients, have found these answers to
be valuable. Moreover we feel that thinking through these issues has
broadened our understanding of how users interact with designs and
how to produce the most actionable results for our clients.
I contend 2 things:
1) A trained observer can get much of this information through what
you call "traditional" means.
2) You can't tell from an eye tracker what the users "sees".
All you can tell from the eye tracking system is what the users
focuses their gaze on. What the user sees requires cognitive effort
the eye tracker doesn't measure. (Anyone who's had the experience of
not seeing the ketchup bottle that is clearly on the shelf in front of
them in the fridge has had the experience of gazing at something
without seeing it. My late wife called this phenomena "male
refrigerator blindness." I'm quite afflicted myself.)
When a consultant looks at eye tracking results and says, "The user
clearly sees X but they don't see Y", they are making shit up.
I know because I've tested this theory many times. Just hand eye
tracking results to three or more "experts" in eye tracking and they
will each report radically different interpretations of the data.
(Bonus test: change the thresholds on the eye tracking so that the
heatmaps and gaze paths all shift around, and it gets even more
entertaining as they try to tell you that the same user on the same
results did radically different things.)
With all due respect to Nick and his team at Catalyst, in my
experience, eye tracking is a tool that consultants use to
differentiate their services from all the consultants that don't have
eye tracking. ("Hire us because we have that eye tracking gizmo and
they don't!") When companies buy eye trackers for internal use, very
few continue to use it after a few months.
As Nick said, it's a great expense and takes real skill and expertise
to operate. Plus, there's no common understanding or best practices on
how to use it. Minor adjustments to the device, such as setting the
capture thresholds, will report radically different results, as it
captures more or less gaze data which can be very noisy. You control
the amount of noise by adjusting the thresholds, but that also can
miss important gaze data. There's no standards or common understanding
as to what the ideal settings are. (In fact, they are very specific to
local lighting conditions, physiology of the subject, and other local
contextual conditions. So, from one day to the next, the device
reports different results.)
The lifetime cost of buying, installing, training, using, and
maintaining an eye tracker in a internal corporate setting can be
equivalent to as many as 40 additional usability sessions a year.
Personally, I'd rather get the data from the 40 additional users than
spend it diddling with an ineffective piece of hardware.
That's my opinion. I'm a researcher who doesn't (any more) use an eye
tracker.
Jared
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