5. The system in claim 4 , wherein: said dictionary generator is adapted to generate a second dictionary of most common words in said second dataset, said vector space model generator is adapted to generate a third vector space model by counting, for each word in said second dictionary, a number of said second documents in which said word occurs, and said cluster generator is adapted to cluster said second documents in said second dataset based on said third vector space model to produce a second dataset cluster.
5. The system in claim 4 , wherein: said dictionary generator is adapted to generate a second dictionary of most common words in said second dataset, said vector space model generator is adapted to generate a third vector space model by counting, for each word in said second dictionary, a number of said second documents in which said word occurs, and said cluster generator is adapted to cluster said second documents in said second dataset based on said third vector space model to produce a second dataset cluster. 6. The system in claim 5 , wherein said cluster generator is adapted to produce an adapted dataset cluster by clustering said second documents in said second dataset using said centroid seeds and said system further comprises: a comparator adapted to compare classes in said adapted dataset cluster to classes in said second dataset cluster and add classes to said adapted dataset cluster based on said comparing.