This project focuses on mechanisms that allow the amalgamation of the ranked hit lists provided by typical search engines in response to user queries, into summary lists that can be used to produce the final list output by a metasearch engine. The techniques used are based mainly on the theory of preference voting. Search engines are viewed as voters in an election in which the winning candidate is the top-ranked hit for a given user query; more generally, the support given by the voting engines to the various candidates (hits) produces the resulting ranking.

Three voting-theoretic methods are compared: Condorcet, Borda count, and plurality with elimination. In addition, a technique based on geometric transformations is compared with the above methods. A prototype system incorporating the above methods has been built. The system adapts to user preferences by maintaining a metaindex that is updated dynamically based on the frequency with which the various search engines have provided links that the user has subsequently followed.