Query Clauses and Term Independence

Much current research in IR, Web-Search and Semantic-Web technologies aims at enriching the user query to gain a richer, more semantic understanding of the information need. Almost in all cases this query enrichment step is approached independently of the ranking function; however, this may be far from optimal. In this paper we discuss the problem of term dependency in the context of query expansion and show its dangers in a number of empirical evaluations. Furthermore we propose a simple method (query clauses) that can be applied to several standard ranking functions to exploit a simple type of term dependency.