1. A method comprising: determining, by a system having a processor, a number of events that share a collection of values of plural attributes; computing, by the system using a contingency calculation based on the number of events, a discriminative metric representing a statistical significance of the events that share the collection of values of the plural attributes; and generating a visualization that includes cells representing respective events, the visualization including a region containing a subset of the cells corresponding to the shared collection of values of the plural attributes, and the visualization including a significance visual indicator associated with the region to indicate the statistical significance of the events sharing the collection of values of the plural attributes.