Atypical Queries in eCommerce

Understanding how specific, ambiguous, or broad the intent of a search query is, across all users of the system, is important in improving search relevance in eCommerce. There is scant literature on such a structural characterization of queries in eCommerce. In this paper, we use query-click log data to address the problem of identifying "atypical queries": these are queries that are extremal in terms of specificity, ambiguity, or breadth of intent. We isolate three components of atypicality: geometric, statistical, and topological. We demonstrate, using query-click logs at Groupon, that certain combinations of these properties render a query atypical, and discuss how search analysts treat such queries differently. Our work is being used to improve search relevance at Groupon.