Making the Most of a Web Search Session

We tackle problems related to Web query formulation: given the set of keywords from a search session, 1) we find a maximum promising Web query, and, 2) we construct a family of promising Web queries covering all keywords. A query is promising if it fulfills user-defined constraints on the number of returned hits. We assume a real-world setting where the user is not given direct access to a search engine´s index, i.e., querying is possible only through an interface. The goal to be optimized is the overall number of submitted Web queries. For both problems we develop search strategies based on co-occurrence probabilities. The achieved performance gain is substantial: compared to the uninformed baselines without co-occurrence probabilities the expected savings are up to 50% in the number of submitted queries, index accesses, and runtime.