2. The method of claim 1 , comprising identifying one or more mislabeled pairs in a pre-existing relevance ranking.
2. The method of claim 1 , comprising identifying one or more mislabeled pairs in a pre-existing relevance ranking. 7. The method of claim 2 , comprising at least one of: determining a longest common subsequence (LCS) of one or more pairs that is decreasing in both the pre-existing relevance ranking and the click relevance ranking; or removing labels from one or more pairs which are not in the LCS.