Generalizations of boolean query processing

Abstract

Substantial work has been done recently applying fuzzy subset theory to the problems of document and query representation and processing in retrieval systems. The motivation has often been to generalize Boolean query processing to allow for non-Boolean index weights or measures of importance to be attached to the individual terms in the document or in the query representation. The problems of generalizing the Boolean lattice structure have been noted. Criteria have been generated for query processing mechanisms with relevance weights in the query, but these have been shown to be inconsistent. An alternative approach using thresholds in the query has been suggested, with the generation of appropriate document evaluation criteria for Boolean query processing.