The Retrieval Effects of Query Expansion on a Feedback Document Retrieval System

Abstract

This paper presents the results of an experimental investigation into the effects that some forms of query expansion by term addition or term deletion, have on the retrieval effectiveness of a document retrieval system. The overall search strategy used by a user is an iterative process whereby a set of user-judged relevant documents at any point in the search is used to refine and improve on the remainder of the user's search. At some point during the search, the set of relevant documents found so far can be used to modify the original query, either by the addition or deletion of search terms. This process is called ‘query modification’ or ‘query expansion’. A number of different types of query modification strategies are tried and the results obtained are presented and analysed.