20. A document clustering apparatus comprising: processing circuitry configured to access a document set comprising a plurality of documents, to define a cluster comprising a subset of the documents of the document set and wherein the subset comprises a plurality of the documents, to identify a cluster label indicative of subject matter content of at least one of the documents of the cluster at least in part by co-occurrence of the cluster label and a plurality of terms of the documents of the cluster which are indicative of the subject matter content of the documents of the cluster, and to use the terms of the documents of the cluster to disambiguate the cluster label after the identification of the cluster label to increase the relevancy of the cluster label with respect to the subject matter content of the at least one of the documents compared with the cluster label prior to the disambiguation.
20. A document clustering apparatus comprising: processing circuitry configured to access a document set comprising a plurality of documents, to define a cluster comprising a subset of the documents of the document set and wherein the subset comprises a plurality of the documents, to identify a cluster label indicative of subject matter content of at least one of the documents of the cluster at least in part by co-occurrence of the cluster label and a plurality of terms of the documents of the cluster which are indicative of the subject matter content of the documents of the cluster, and to use the terms of the documents of the cluster to disambiguate the cluster label after the identification of the cluster label to increase the relevancy of the cluster label with respect to the subject matter content of the at least one of the documents compared with the cluster label prior to the disambiguation. 32. The apparatus of claim 20 wherein the documents of the cluster individually comprise a plurality of words.