4. The method of claim 2 , including: extracting first structured features and unstructured features of the third set of documents, wherein the first structured features comprise author, assignee, and classification of each of the third set of documents, and documents referenced by each of the third set of documents.
4. The method of claim 2 , including: extracting first structured features and unstructured features of the third set of documents, wherein the first structured features comprise author, assignee, and classification of each of the third set of documents, and documents referenced by each of the third set of documents. 5. The method of claim 4 , including: converting the extracted unstructured features of the third set of documents to second structured features of the third set of documents.