Yahoo Inc., said on Monday named a top academic database expert to head its research team studying links between computer and human-aided Web search.

Yahoo hired Raghu Ramakrishnan, 45, as vice president and Yahoo research fellow in charge of defining the strategy behind Yahoo's social search system, based on his expertise in databases, data-mining and privacy-preserving technologies.

Social search - a broad effort to enhance computerized Web- search tools with insights gained from mining the collective knowledge of its users - is the linchpin of Yahoo's strategy to compete with rival Google Inc., which has focused heavily on advances in computerized search.

At Yahoo you have this unique opportunity to integrate conventional search with Flickr,, Yahoo Answers, Yahoo Groups and Yahoo Mail, Ramakrishnan said, listing Yahoo's services that center on human contributions. How do you take all this search activity and learn from it?

Ramakrishnan was for nearly 20 years a computer science professor at the University of Wisconsin, Madison, and a co-founder of the university's Data Mining Institute. He is co-author of the widely read text, Database Management Systems, and has published over 150 research papers in his career.

How do you make all of this (search activity) as natural as possible to users? There is a big gap between the two subjects, Ramakrishnan said.

In 1999, he co-founded and served as chairman and chief technology officer of QUIQ, a company that pioneered online question-answering communities and collaborative customer Web self-service for companies such as Business Objects, Compaq and Sun Microsystems Inc..

Ramakrishnan will be based at Yahoo's research facility near its Sunnyvale, California headquarters and will report to the head of Yahoo Research, Prabhakar Raghavan.

He holds an undergraduate degree from the Indian Institute of Technology (IIT) at Madras and a Ph.D. from the University of Texas at Austin. He chairs the Association for Computing Machinery (ACM) Special Interest Group on Management of Data, is a fellow of the ACM and recipient of the David and Lucile Packard Foundation Fellowship in Science and Engineering.