19. The computer program product of claim 18 , wherein the operations further comprise: clustering a plurality of second documents into one or more second document groups, wherein each of the one or more second document groups is associated with a respective author proper name; for each of the one or more second document groups: determining a correspondence score for the second document group in reference to the author profile for the author; determining whether or not the correspondence score satisfies a threshold; and when the correspondence score satisfies the threshold, including data identifying the second documents in the second document group as documents authored by the author in the author profile for the author.
19. The computer program product of claim 18 , wherein the operations further comprise: clustering a plurality of second documents into one or more second document groups, wherein each of the one or more second document groups is associated with a respective author proper name; for each of the one or more second document groups: determining a correspondence score for the second document group in reference to the author profile for the author; determining whether or not the correspondence score satisfies a threshold; and when the correspondence score satisfies the threshold, including data identifying the second documents in the second document group as documents authored by the author in the author profile for the author. 20. The computer program product of claim 19 , wherein the correspondence score is based on a count of documents that are in both the second document group and in the author profile, a count of documents that are in the second document group and have never been in the author profile, a count of documents that are in the second document group and have been removed from the author profile.