Discusses the probabilistic nature of information retrieval, and describes a front end system designed to permit searchers to attach probabilistically interpreted weights to query terms, which could be adapted for conventional information retrieval systems without requiring radical changes in current indexing procedures. (37 references) (CLB)

Provides an overview of methods for improving the effectiveness of Boolean retrieval systems, including document clustering, relevance feedback, weighted term searching, ranked output, and fuzzy set theory. The discussion of experimental studies with the SMART and SIRE systems focuses on the implementation and results of these methods. (69…