A prevalence formula for automatic relevance feedback in Boolean systems

摘要

The implementation of relevance feedback explored here demonstrates the feasibility of query reformulation for boolean retrievals. Improvements to a term prevalence formula used in earlier research are presented along with experimental results that confirm the crucial role of term weights in relevance feedback. In particular, the weighting formula presented here differs significantly from those used by researchers in associative retrieval environments by giving equal weight to a patron's judgements of nonrelevance. The use of negative feedback—by NOTing terms in the negative prevalence range—failed to improve precision, a result that is also considered significant.