A Study of Immediate Requery Behavior in Search

When search results fail to satisfy users» information needs, users often reformulate their search query in the hopes of receiving better results. In many cases, users immediately requery without clicking on any search results. In this paper, we report on a user study designed to investigate the rate at which users immediately reformulate at different levels of search quality. We had users search for answers to questions as we manipulated the placement of the only relevant document in a ranked list of search results. We show that as the quality of search results decreases, the probability of immediately requerying increases. We find that users can quickly decide to immediately reformulate, and the time to immediately reformulate appears to be independent of the quality of the search results. Finally, we show that there appears to be two types of users. One group has a high probability of immediately reformulating and the other is unlikely to immediately reformulate unless no relevant documents can be found in the search results. While requerying takes time, it is the group of users who are more likely to immediately requery that are able to able find answers to questions the fastest.