When seeking information with a search engine, under which circumstances do you modify your queries in order to retrieve better results, e.g., by adding or removing terms? In this paper, we investigate the motivation behind query modifications. Here is the abstract:
In the course of a search session, searchers often modify their queries several times. In most previous work analyzing search logs, the addition of terms to a query is identified with query specification and the removal of terms with query generalization. By analyzing the result sets that motivated searchers to make modifications, we show that this interpretation is not always correct. In fact, our experiments indicate that in the majority of cases the modifications have the opposite functions. Terms are often removed to get rid of irrelevant results matching only part of the query and thus to make the result set more specific. Similarly, terms are often added to retrieve more diverse results. We propose an alternative interpretation of term additions and removals and show that it explains the deviant modification behavior that was observed.