An example method is provided in according with one implementation of the present disclosure. The method comprises scoring a plurality of classifiers on a guidance set of example items in a dataset of items, and selecting the best scoring classifier. The method also comprises determining a group of residual items in the dataset, and applying the selected classifier to the residual items in the dataset. The method further comprises partitioning the residual items in the dataset into a plurality of groups according to the outputs of the selected classifier, and outputting at least one group from the plurality of groups.
