In order to provide a non-factoid question answering system with improved accuracy, the question answering system (160) includes: a candidate searching unit (222) which in response to a question extracts answer candidates from a corpus storage unit (178); a feature vector generation unit (232) which generates features for combinations of a question with each of the answer candidates; an SVM (176) which is trained to calculate a score of how correct a combination of the question with an answer candidate is, upon receiving the feature vector therefor; and an answer ranking unit (234) which outputs the answer candidate with the highest score calculated as the answer. Features are generated on the basis of the results of morphological analysis and syntactic analysis of the question, a phrase in the question evaluated as being positive or negative as well as the polarity thereof, and the semantic classes of the nouns in the features.
NON-FACTOID QUESTION ANSWERING SYSTEM AND COMPUTER PROGRAM