Jon Kleinberg
Cornell University

Computational Perspectives on Social Phenomena in On-Line Networks
photo of Jon Kleinberg​Abstract: With an increasing amount of social interaction taking place in the digital domain, and often in public online settings, we are accumulating enormous amounts of data about phenomena that were once essentially invisible to us: the collective behaviour and social interactions of hundreds of millions of people, recorded at unprecedented levels of scale and resolution. Analyzing this data computationally offers new insights into the design of online applications, as well as a new perspective on fundamental questions in the social sciences.

We discuss how this perspective can be applied to questions involving network structure and the dynamics of interaction among individuals, including analysis of data from the online domain as well as mathematical models that seek to abstract some of the underlying phenomena.

Biography: Jon Michael Kleinberg (born October 1971) is an American computer scientist, MacArthur Fellow, Nevanlinna Prize winner, and the Tisch University Professor of Computer Science at Cornell University. Jon Kleinberg was born in 1971 in Boston, Massachusetts. He received a BS in computer science from Cornell University in 1993 and a PhD, also in computer science, from the Massachusetts Institute of Technology (MIT) in 1996.

Since 1996 he has been a professor in the Department of Computer Science at Cornell, as well as a visiting scientist at IBM's Almaden Research Center. His work has been supported by an NSF Career Award, an ONR Young Investigator Award, a MacArthur Foundation Fellowship, a Packard Foundation Fellowship, a Sloan Foundation Fellowship, and grants from Google, Yahoo!, and the NSF. He is a member of the National Academy of Engineering and the American Academy of Arts and Sciences.

Kleinberg is best known for his work on networks and particularly for his HITS algorithm, developed while he was at IBM. HITS is an algorithm for web search that builds on the eigenvector-based methods used in algorithms and served as the full scale model for PageRank by recognizing that web pages or sites should not only be considered important (as in PageRank) if they are linked to by many others, but also if they link to many others. Search engines themselves are examples of sites that are important because they link to many others.

Kleinberg realized that this generalization implies two different classes of important web pages, which he called "hubs" and "authorities". The HITS algorithm is an algorithm for automatically identifying the leading hubs and authorities in a network of hyperlinked pages. Kleinberg is also known for his work on algorithmic aspects of the small world experiment. He was one of the first to realize that Stanley Milgram's famous "six degrees" letter-passing experiment implied not only that there are short paths between individuals in social networks but also that people seem to be good at finding those paths, an apparently simple observation that turns out to have profound implications for the structure of the networks in question.

Kleinberg has written numerous papers and articles as well as a textbook on computer algorithms, Algorithm Design, co-authored with Éva Tardos. Among other honours, he received a MacArthur Foundation Fellowship also known as the "genius grant" in 2005 and the Nevanlinna Prize in 2006, an award that is given out once every four years along with the Fields Medal as the premier distinction in Computational Mathematics. His new book is entitled Networks, Crowds, and Markets: Reasoning About a Highly Connected World and will be published by Cambridge University Press in 2010.