Google "personalizes" as much as 20 per cent of your web searches, according to Mountain View software engineer Bryan Horling.
Speaking this afternoon at the search-obsessed SMX West conference in Santa Clara, Horling - a developer with Google's personalized search team - said that up to one in five searches are tailored to the user's particular location, web history, or online contacts. "As it stands today," Horling explained, "between these three techniques, just about every user who's engaging with Google search today is affected."
This does not include search results that Google tailors to particular countries or continents. If you search for "taxes," for instance, results in the US will differ widely from those in the UK. In the US, you'll get info from the IRS. In the UK, you'll get stuff from HM Revenue & Customs Page.
Google has tweaked results from country to country for years. Now, it's tweaking results based on the individual user's behavior. But Horling emphasized that many of these changes are rather subtle. "When these techniques fire, the changes tend to relatively minor," he said. "We're moving a few results. We might be moving a few down. We're generally not changing the entire character of the page."
Horling and team avoid making sweeping changes for two reasons. "For one, when we have information related to the user, it tends to be pretty clear what they're looking for," Horling explained. "And the second is that we're not always right. We're inferring information or trying to fill in the context, but we don't always get it right."
We would argue that these two points are somewhat contradictory, but there you have it.
In early December, Mountain View began personalizing search for users even when they're not signed in to a Google account, tailoring results according to the web history attached to a particular set of browser cookies on the user's machine. Now, anyone who uses the company's search engine, whether they're signed in or not, is subject to this so-called personalization.
Google is also tailoring results to the user's particular metropolitan area or local region. If you ask for a bus schedule, for instance, it will attempt to give you a bus schedule for your particular city. "For years, we've been personalizing for an entire continent [or country]," Horling said. "More recently, what we've started doing is taking the same intuition but applying it at a finer granularity."
And, yes, Mountain View is tweaking results according to the personal contacts you've set up in applications like Gmail or Google Chat, the people you're "following" on Google Buzz, and other online relationships that Google infers from such contacts. Google calls this "social" search. "The idea behind social search is that we surface content from your social circle," he said. If you know a particular person, for instance, Google may ensure that a document they wrote receives particular prominence on the results page.
When Google began personalizing results for signed-out users, many webmasters and search engine optimizers (SEO) cursed the company to the high heavens, miffed that they can no longer ensure that their sites always appear at the top of Mountain View's results page. But Horling said that personalization is the only way to truly refine the search process, and he urged webmasters and SEOs to concentrate on improving their sites will particular users in mind - as opposed to with Google in mind.
"You should be creating compelling and interesting content that's focused on the user," Horloing said. "You website should be fast. It should be clean. It should be understandable. It should be compelling enough that users want to return to use it."
Which is what Google has always said. ®