An extended relevance model for session search

The session search task aims at best serving the user's information need given her previous search behavior during the session. We propose an extended relevance model that captures the user's dynamic information need in the session. Our relevance modelling approach is directly driven by the user's query reformulation (change) decisions and the estimate of how much the user's search behavior a.ects such decisions. Overall, we demonstrate that, the proposed approach significantly boosts session search performance.