Briefs

Feb 15, 2004. Newswise.

"Does the flap of a butterfly's wings in Brazil set off a tornado in Texas?" ...

Sociologists postulate that what a few influential leaders think and say can spread and grow and bring about big changes in the thinking of large numbers of people. ... But how do you find those influential people?

Jon Kleinberg, Cornell professor of computer science, discussed the problem, and some computer algorithms to solve it, in a talk on Feb. 15 at the annual meeting of the American Association for the Advancement of Science (AAAS) in Seattle. His talk was part of a symposium on "Community Structure of the Internet and World Wide Web: Mathematical Analyses."

Groups on the Internet can take many forms, including Usenet and chatroom discussion groups, e-mail mailing lists and links between Web sites on related topics. Most recently, the writers of personal online journals known as Web logs, or "blogs," have begun to link to one another and comment on each other's work.One way to find the influential people would be to identify those who have the most links to others, or the ones who can reach the largest number of others with the fewest "hops" through other people. That, Kleinberg says, introduces redundancy: the two or three top candidates could all link to the same subset of the network. So, Kleinberg suggests, "After targeting the first few people you discount others, then you look for people who are still influential but in diverse parts of the network."

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