Patent Document ID: 9020936
Application ID: 12541166

Base Claim:
1. A method executed by a search engine for ranking items responsive to receipt of a query, the method comprising: at the search engine, responsive to receiving the query that is to be executed over a plurality of items in a data repository, identifying a document-query feature that pertains to a combination of the query and an item in the plurality of items, wherein the document-query feature is based upon: a document category that has been previously assigned to the item; and a query category that has been previously assigned to the query, wherein the query category is dependent upon document categories assigned to items previously retrieved by the search engine when executing the query over a data repository, the document-query feature is indicative of a correlation between the document category and the query category; at the search engine, retrieving items from the data repository based upon the query; ranking the items based upon document-query features assigned to the items; and responsive to ranking the items, outputting a ranked list of items, the item positioned in the ranked list of items based upon the document-query feature.

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Claim 4:
4. The method of claim 1 , further comprising assigning the query category to the query, wherein assigning the query category to the query comprises: accessing a click graph, the click graph comprises a first set of nodes and a second set of nodes, edges couple nodes in the first set of nodes with nodes in the second set of nodes, nodes in the first set of nodes are representative of queries, nodes in the second set of nodes represent items, and an edge between a node in the first set of nodes and a node in the second set of nodes indicates that a user has clicked on an item represented by the node in the second set of nodes upon issuing a query represented by the node in the first set of nodes to the search engine; analyzing the click graph to determine items that were previously clicked by users that issued the query to the search engine when the query was issued to the search engine by the users; determining document categories assigned, respectively, to the items that were clicked on by the users when the query was issued; and assigning the query category to the query based upon the document category being assigned to at least one item in the items that were clicked on by the users when the query was issued.