Google Inc. is looking to find more links between the searches its users do in order to better target advertising, but the company is reluctant to go much further than that in tracking their behavior.

Susan Wojcicki, Google vice president of product management for advertising, said on Tuesday Google was shying away from the industry race to deliver tools for advertisers that stitch together a user's various online actions into one profile.

The world's Web search leader has built its business around ads tied to words typed into its search box, which are expected to earn it upward of $16 billion in revenue this year.

In seeking patterns, Google's plans involve tracking the various words typed in a given search session, as opposed to building a deeper user profile over time. The latter is known broadly as behavioral targeting, which has long been seen by many as the Holy Grail of the online ad business, but inevitably raises issues about personal privacy.

That is not something that we have participated in, for a variety of reasons, Wojcicki told reporters at a briefing at the company's headquarters in Mountain View, California.

We believe that task-based information at the time (of a user's search) is the most relevant information to what they are looking at, she said. We always want to be very careful about what information would or would not be used.

At issue is not only users' sense of privacy, but the success of Google's existing business tying Web searches to related ad links, she said. Plus, the intentions of users can be elusive based on any given set of actions.

Google's planned acquisition of advertising tools supplier DoubleClick Inc. and the growing level of integration between its various services have raised concerns among privacy advocates over the potential to abuse its growing power.

INFERRING FROM THE LAST SEARCH

Google has been testing for several weeks a new advertising feature that delivers ads based not simply on a specific search term, but also on the immediately previous search, she said.

A user who types Italy vacation into a Google search box might see ads about Tuscany or cheap flights to Europe. Were the same user to subsequently search for weather, Google will assume there is a link between Italy vacation and weather and deliver ads tied to local weather conditions in Italy.

While expanding beyond one-for-one correspondence between a consumer's Web search and the ads displayed, Google says its ad targeting remains rooted in search activity rather than trying to deduce relationships from other sorts of user information.

The Google official stressed that this effort to improve ad relevancy does not involve personal information databases.

What we are very careful about is traditional behavioral targeting, Wojcicki said. Nothing is stored, nothing is remembered. It all happens within that session.

The longtime Google executive, whose garage became its headquarters when Larry Page and Sergey Brin first set up the company, said Google was hesitant about drawing too many conclusions about users from search terms.

Wojcicki highlighted the problem of a user searching video games. Advertisers might be wrong to assume the searcher was a gamer and not, say, a grandmother, looking for a gift for her grandson, she noted.

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