When Jennifer Chayes left her job at the University of California, Los Angeles, in 1997 to become a researcher at Microsoft's labs in Redmond, she declared that it would take 100 years for her academic work to find real-world applications. But as managing director of the newly announced Microsoft Research New England lab in Cambridge, MA, she has parlayed her background in mathe­matical physics into research with broad implications for today's Internet.

To Chayes, the trails left by countless social and business interactions on the Internet amount to enormous math problems. Solving those problems, she believes, will help computer scientists create online tools, such as search engines and social networks, that are more efficient and effective.