39. The computer program product of claim 38 , wherein the correspondence score for each document group is based on a count of documents that are in both the document group and in the particular author profile, a count of documents that are in the document group and have never been in the particular author profile, and a count of documents that are in the document group and have been removed from the particular author profile.
38. The computer program product of claim 37 , the operations further comprising assigning to the particular author profile one or more additional document groups, comprising: determining a correspondence score for each of one or more of the document groups in reference to the particular author profile; determining that the correspondence score for a first document group of the one or more document groups satisfies a threshold; and adding documents in the first document group to the particular author profile as documents authored by the particular author.