14. The computer system of claim 13 , wherein while extracting the first set of knowledge relevant to the document, the first knowledge extraction mechanism is configured to derive a set of words or phrases relevant to each document.
14. The computer system of claim 13 , wherein while extracting the first set of knowledge relevant to the document, the first knowledge extraction mechanism is configured to derive a set of words or phrases relevant to each document. 15. The computer system of claim 14 , wherein while deriving the set of words or phrases, the first knowledge extraction mechanism is further configured to determine a term-frequency inverse-document-frequency (TF.IDF) weight for a word or phrase contained in the document.