Abstract

Information agents answer user queries using a large number of diverse information sources. The key issue in their perfomance is nding the set of information sources relevant to a query. Previous work has considered determining relevance soley based on compile-time analysis of the query. We argue that at compile-time, it is often not possible to signi cantly prune the set of sources relevant to a query, and that run-time information is needed. We make the following contributions. First, we identify the di erent types of information that can be obtained at run-time, and how they can be used to prune information sources. Second, we describe an algorithm which naturally extends query planning algorithms to exploit run-time information. Third, we describe the discrimination matrix, which is a data structure that identi es the information that can be used to help discriminate between di erent possible sources.

Date

September 22, 1995

Authors

Craig A Knoblock, Alon Y Levy

Journal

Working Notes of the AAAI Spring Symposium on Information Gathering from Heterogeneous, Distributed Environments, Stanford, CA