Google is renowned for its intuitive user interface—but a lot of work goes in to making sure that Google understands exactly how its users interact with its pages, as evidenced in a blog post yesterday. And Google doesn’t just look at the user data they get from clicks or surveys—they use actual field studies.

Are actual field tests, observing users “in the wild,” necessary? Google’s Search Quality Uber Tech Lead, Daniel Russell, explains why:

people are masters of saying one thing and doing another, particularly when it comes to nearly automatic behavior. We find that searchers often turn so quickly to Google that they don’t really think too much about what they’re actually searching for.

It’s surprising, but often we’ll see people trying to find out something about a topic, but then never actually mention the topic itself. That is, there’s often a big discrepancy between what they’ll tell me (the human observer) they’re trying to do, and the search terms they enter into Google. One person I shadowed for the day spent ten minutes trying to find the schedule of the ferry that runs between San Francisco and Larkspur, but somehow only thought of adding the word “ferry” much later in their search. . . .

Memories of your own behavior are also notoriously unreliable. People’s search behavior in the lab is often different than when they’re at home or at work. This is a natural (and expected) side effect of lab studies: people will work especially hard to please a researcher.

If we ask them to search for a pair of brown shoes they’d like to buy for themselves, in the lab they’ll find the first pair that seems reasonable and then stop, satisfied. If it was real, they would go on and spend more time. We still do lab studies, but we know what to watch for, and what to ignore.

Not the most heartening observation of human intelligence I’ve ever heard…

Anyway, Google also uses tools like eyetracking in this example (the red dot indicates the user’s gaze):

Google also puts this data to use, such as in the overhaul of their Advanced Search page.

What do you do to learn more about how your users interact with your site?