1. A method for detecting and coordinating change events in a data stream, comprising: receiving the data stream, the data stream comprising a plurality of lexical items and a metavalue associated therewith; monitoring a probability of occurrence of the lexical items in the data stream over time according to a lexical occurrence model to detect a plurality of change events in the data stream; applying a significance test to the change events to determine if the change events are statistically significant; applying an interestingness test to determine if the change events are likely to be of interest to a user, the interestingness test defined using conditional mutual information between the lexical items and the lexical occurrence model given a time span to determine an amount of information that is derived from the change events; grouping the change events across the lexical items and the metavalue to summarize the change events that are synchronous in time, the grouping forming a set of grouped change events; and presenting, via an output device, a summarization of the grouped change events to the user.