Sep. 22--When Yahoo CEO Carol Bartz announced a $100 million global brand campaign in New York Tuesday as the company launched its new Internet search "experience," research scientists like Preston McAfee, Duncan Watts and David Reiley were not in the spotlight.

Yet the three scientists, who recently quit tenured posts at leading U.S. universities to join Yahoo Labs, are a crucial part of Yahoo as it tries to improve the flagging popularity of its search engine and attract audiences to its other products, including e-mail, instant messaging and software for mobile devices.

In a press conference at the NASDAQ headquarters to announce the multi-platform "It's Y!ou" campaign that will play in the U.S. and nine other countries around the world over the next 15 months, Bartz said Yahoo believes it can build its search audience by focusing on the user "experience," rather than viewing search as a raw data query.

A basic Web search, Bartz told reporters, is like an Intel chip -- a common ingredient many computer makers use to create their distinct products.

"The experience that H-P wraps around those chips is different than the experience Dell wraps around those chips," Bartz said. "We are looking to focus our research and our scientists on the experience around that basic information. So search is vital for us."

Yahoo's decision to focus on the "front-end" human experience of search provides a window into its strategy in its heavily

criticized search partnership with Microsoft, which was panned by investors and many analysists when the deal did not include a hefty upfront payment from Microsoft. And what's notable about many of the stable of researchers at Yahoo backing that effort is that many of them, including McAfee, Watts and Reiley, aren't even computer scientists.

They are part of a team of social scientists -- cognitive psychologists, sociologists, economists and ethnographers -- that Yahoo hopes will help close the search gap with the dominant Google. Analysts say that effort is crucial to Yahoo's future.

"You have to fix search," said Karsten Weide, an analyst with the research firm IDC who was initially critical of Yahoo's partnership with Microsoft.

The plan to broaden Yahoo Labs into a multidisciplinary team where social scientists work directly with computer scientists is one element of Yahoo's strategy to hold people on its Web properties, after its new branding campaign -- Yahoo's single largest integrated global campaign ever -- brings them in the door.