18. The computer program product of claim 17 , wherein the instructions to select the subset of the set of television program identifiers most closely related to the selected metadata tag further comprise instructions to identify nodes with distance values greater than a predetermined threshold value.
17. The computer program product of claim 11 , wherein the instructions to select the subset of the set of television program identifiers most closely related to the selected metadata tag further comprise instructions to generate a distance value, for each node of the plurality of nodes representing a television program identifier, based on a degree of separation between the node and a node representing the selected metadata tag in the graph data structure.