15. The computer readable storage device of claim 14 , wherein determining the relevance of the first set of documents relative to the second set of documents is further based on (i) a relevance of the first category of documents to the search query, and (ii) a relevance of the second category of documents to the search query.
15. The computer readable storage device of claim 14 , wherein determining the relevance of the first set of documents relative to the second set of documents is further based on (i) a relevance of the first category of documents to the search query, and (ii) a relevance of the second category of documents to the search query. 16. The computer readable storage device of claim 15 , wherein the operations further comprise: determining the relevance of the first category of documents to the search query based on a comparison of at least one term included in the search query to one or more terms that correspond to the first category; and determining the relevance of the second category of documents to the search query based on a comparison of at least one term included in the search query to one or more terms that correspond to the second category.