Combining thesauri-based methods for biomedical retrieval

This paper describes our participation in the TREC 2005 Genomics track. We took part in the ad hoc retrieval task and aimed at integrating thesauri in the retrieval model. We developed three thesauri-based methods, two of which made use of the existing MeSH thesaurus. One method uses blind relevance feedback on MeSH terms, the second uses an index of the MeSH thesaurus for query expansion. The third method makes use of a dynamically generated lookup list, by which acronyms and synonyms could be inferred. We show that, despite the relatively minor improvements in retrieval performance of individually applied methods, a combination works best and is able to deliver significant improvements over the baseline