To improve coverage, reliability, diversity and stability of an answer by utilizing a plurality of knowledge sources different in language in a question answering system.
This question answering system requests the answer by using a first knowledge database having the knowledge source of first language and a second knowledge database having the knowledge source of second language on a question inputted in the first language by a user, and acquires an answer candidate for the first language by retrieving the first knowledge database on the question. The question is mechanically translated into the second language, and an answer candidate for the second language is acquired by retrieving the second knowledge database. Here, the answer candidate for the second language is mechanically translated into the first language. The whole mechanical translation results to the first language of the answer candidate for the first language and the answer candidate for the second language are ranked on the basis of a prescribed reference, and are presented to the user.
Sadao Muramatsu
Atsushi Tsuboi
Ryo Hashimoto
Satoshi Kono
Makoto Nakamura
Shoji Kawai