15. A system comprising: a computer system; and a related query processor of the computer system to determine a score for a document as a result for a search query, the score based, at least in part, on one or more related search queries that have at least a threshold relationship to the search query, wherein the score is determined by performing operations comprising: identifying click data associated with the document and the one or more related search queries, wherein the click data indicates how frequently the document was selected when the document was presented in search results for the one or more related search queries over a period of time; weighting the click data based on weights for the one or more related search queries, wherein the weights indicate how strongly the one or more related queries are related to the search query; and combining the weighted click data to generate at least a component of the score; wherein the related query processor is further configured to provide the score for the document as a result for the search query to a ranking processor.
15. A system comprising: a computer system; and a related query processor of the computer system to determine a score for a document as a result for a search query, the score based, at least in part, on one or more related search queries that have at least a threshold relationship to the search query, wherein the score is determined by performing operations comprising: identifying click data associated with the document and the one or more related search queries, wherein the click data indicates how frequently the document was selected when the document was presented in search results for the one or more related search queries over a period of time; weighting the click data based on weights for the one or more related search queries, wherein the weights indicate how strongly the one or more related queries are related to the search query; and combining the weighted click data to generate at least a component of the score; wherein the related query processor is further configured to provide the score for the document as a result for the search query to a ranking processor. 18. The system of claim 15 , wherein the operations further comprise combining additional click data with the combined weighted click data to generate the score, wherein the additional click data indicates how frequently the document was selected when the document was presented in search results for the search query.