5. The computer-implemented method of claim 4 , wherein computing the total order of nodes comprises calculating: a Kendall score for at least one node in the complete directed graph.
4. The computer-implemented method of claim 1 , wherein the preference graph comprises a plurality of nodes, wherein each node corresponds to an item in the plurality of items, and wherein calculating the ranking comprises: computing a total order of nodes in a complete directed graph derived from the preference graph.