8. The computer-readable medium according to claim 7 , wherein: each response record comprises an inquiry content field containing details of an inquiry and a response content field containing details of a response to the inquiry; and the large category classifying unit retrieves the keywords from either or both of the inquiry content field and the response content field.
7. The computer-readable medium according to claim 1 , wherein: the classification rules each give a particular large category name in association with a set of keywords that are supposed to appear in response records of that large category; and the large category classifying unit retrieves the keywords contained in the response records and, based on the classification rules, allocates to the response records the large category name associated with the retrieved keywords.