1. In a computing environment, a method comprising, employing at least one processor to perform steps comprising: obtaining lambda gradient scores for pairs of ranked sample data items; using the lambda gradient scores to compute re-judgment scores for the ranked sample data items, wherein each lambda gradient score includes a ranking cost for a pair of ranked sample data items; and selecting one or more ranked sample data items of the ranked sample data items for relabeling based upon a re-judgment score associated with each ranked sample data item, wherein the re-judgment score indicates a likelihood of mislabeling a corresponding ranked sampled data item.