The effect of accessing nonmatching documents on relevance feedback

Traditional information retrieval (IR) systems only allow users access to documents that match their current query, and therefore, users can only give relevance feedback on matching documents (or those with a matching strength greater than a set threshold. This article shows that, in systems that allow access to nonmatching documents (e.g., hybrid hypertext and information retrieval systems), the strength of the effect of giving relevance feedback varies between matching and nonmatching documents. For positive feedback the results shown here are encouraging, as they can be justified by an intuitive view of the process. However, for negative feedback the results show behavior that cannot easily be justified and that varies greatly depending on the model of feedback used.