RMIT University at TREC 2008: Relevance Feedback Track

This report outlines TREC-2008 Relevance Feedback Track experiments done at RMIT University. Relevance feedback in text retrieval systems is a process where a user gives explicit feedback on an initial set of retrieval results returned by a search system. For example, the user might mark some of the items as being relevant, or not relevant, to their current information need. This feedback can be used in different ways; one approach is query expansion, where terms from the relevant documents are added to the original query, with the aim of improving retrieval effectiveness. This report describes the the query expansion methods that we explored as part of TREC 2008. Our results demonstrate that high weight terms are not always necessarily useful for query expansion.