Language Models for Enterprise Search: Query Expansion and Combination of Evidence

We describe our participation in the TREC 2006 Enterprise track. We provide a detailed account of the ideas underlying our language modeling approaches to both the discussion search and expert search tasks. For discussion search, our focus was on query expansion techniques, using additional information from the topic statement and from message threads; while the former was generally helpful, the latter mostly hurt performance. In expert search our main experiments concerned query expansion as well as combinations of expert finding and expert profiling techniques.