13. The computer-implemented method of claim 10 , wherein the text content comprises an article, a comment, an email or message containing user feedback or discussion related to a product or service, wherein the first information type refers to a problem being reported or a request for information, and the second information type refers to a sub-type of the problem or a sub-type of the request for information, wherein the sub-type of the problem or the sub-type of the request for information is related to at least an operating procedure, a product feature or function, or a price.
14. The method of claim 13 , wherein text unit representing the request for information includes a question sentence.