Rijke. Language Models for Enterprise Search Query Expansion and Combination of Evidence.pdf

Language Models for Enterprise Search: Query Expansion and Combination of Evidence Krisztian Balog Edgar Meij Maarten de Rijke ISLA, University of Amsterdam http://ilps.science.uva.nl/ Abstract: We describe our participation in the 2 Discussion Search TREC 2006 Enterprise track. We provide a de- tailed account of the ideas underlying our lan- The aim of the discussion search task is to retrieve email guage modeling approaches to both the discus- messages that contain a discussion about a given topic, sion search and expert search tasks. For discus- where highly relevant documents should introduce a new sion search, our focus was on query expansion point to the discussion (such as pro or con given the topic). techniques, using additional information from the This year, our aim for the discussion search task was to ex- topic statement and from message threads; while periment with various query expansion techniques. First, we the former was generally helpful, the latter mostly employed blind relevance feedback, but instead of simply hurt performance. In expert search our main ex- using the top ranked documents, we also included the con- periments concerned query expansion as well as tents of the accompanying threads. Next, we enriched the combinations of expert finding and expert profil- query by adding noun phrases from the description and nar- ing techniques. rative fields.