16. The computer-readable medium of claim 15 , wherein each of a plurality of branches of the decision tree comprises a logged data element independent of a content of the search query.
15. The computer-readable medium of claim 13 , wherein classifying a relevance for the at least one of the plurality of search results according to the logged data element comprises assigning a confidence to the at least one of the plurality of search results according to a decision tree, wherein at least one branch of the decision tree comprises the logged data element.