1. A method of operating a search system, the method comprising: receiving a user query; identifying, from a corpus of data, a result set comprising information about a plurality of items, each of the plurality of items being associated with data in the corpus, the result set being identified based on the query; selecting a value of an attribute from a set of attribute values characterizing assets in the corpus, the selected attribute value being selected based on a ranking of attribute values in the set of attribute values, the ranking being based on a degree of discrimination among items in the result set that results from qualifying inclusion in the result set based on the selected attribute value.