1. A method of content filtering in a discovered topic comprising: preprocessing querying data, said querying data having caused a retrieval of a collection of documents, said collection of documents comprising documents having content comprising related subject matter and comprising documents having content comprising extraneous subject matter, relative to said querying data; clustering said collection of documents in accordance with said querying data, said clustering enabling said discovered topic to be identified, said discovered topic relative to said querying data; and postfiltering said collection of documents to generate a collection of documents having content comprising said related subject matter relative to said topic, wherein extraneous subject matter are excluded.