Authoritative sources in a hyperlinked environment

The network structure of a hyperlinked environment can be a rich source of information about the content of the environment, provided we have effectiv e means for understanding it. We develop a set of algorithmic tools for ext racting information from the link structures of such environments, and repo rt on experiments that demonstrate their effectiveness. in a variety of con texts on the World Wide Web. The central issue we address within our framew ork is the distillation of broad search topics, through the discovery of "a uthoritative" information sources on such topics. We propose and test an al gorithmic formulation of the notion of authority, based on the relationship between a set of relevant authoritative pages and the set of "hub pages" t hat join them together in the link structure. Our formulation has connectio ns to the eigenvectors of certain matrices associated with the link graph; these connections in turn motivate additional heuristics for link-based ana lysis.