1. A computer method for evaluating data, the method comprising performing operations on at least one data processing device, the operations comprising: maintaining an embodiment of a weighted, directed graph representation of the data on a machine readable medium, the embodiment including representations of nodes, links, link weights, and random walk results indicating proximity of nodes to one another; receiving indications of a source and target node within the graph; receiving side information indicating positive and/or negative feedback relating to nodes of the graph; and providing a machine readable embodiment of an indication of an updated proximity between the source and target node, responsive to the side information, without recalculating random walk results for the entire graph, the indication being embodied on a medium.