Fig. 1

Comparison of two example network partitions under the NEC statistic. Edges are omitted for visual clarity and only a single function f is considered in this simple case. The clusters outlined in bold blue are “enriched” and those outlined in dotted red are not. Although the lower partition is more specific for f (i.e. its enriched clusters contain fewer false positives), by the NEC statistic it does not score as well as the upper partition. Note that in this case, the distribution of cluster sizes is indeed much different between partitions; that is, the upper partition has a single giant cluster, and the lower partition contains clusters having a more uniform size distribution