INFORMATION RETRIEVAL USING DYNAMIC EVIDENCE COMBINATION

A system and method for improving information retrieval effectiveness by dynamically combining evidence information produced by a plurality of retrieval systems matching alternative representations of queries and documents. The user enters a query and the system generates alternative representations of the query. The system also maintains a collection of documents and corresponding alternative representations of the documents. The system then performs matching between the alternative representations of the query and the corresponding alternative representations of the documents and generates individual matching scores for the alternative representation matches. Correlation information is also determined for the individual scores. The individual matching scores are combined using a dynamic combination regime which is adjusted for the query. The dynamic combination regime may be a function of query specific information, retrieved documents specific information, or correlation information. The documents are ranked based on the combined scores. The user may also mark specific documents as being relevant. This relevance feedback information may also be used to modify the dynamic combination regime.