摘要 |
PROBLEM TO BE SOLVED: To precisely extract evaluation information by estimating a certainty factor for an evaluation expression.SOLUTION: An evaluation expression extraction part 226 extracts an evaluation expression from a set of documents associated with a specific object to be evaluated and including evaluation expressions, and also extracts a pair of a meaning label representing the meaning of a function expression of a predicate included in a sentence including the extracted evaluation expression and the extracted evaluation expression. A certainty factor estimation part 230 estimates a certainty factor of each evaluation expression extracted by the evaluation expression extraction part based upon a previously learnt estimation model for estimating the certainty factor of the evaluation expression included in the sentence including the function expression of the predicate corresponding to the meaning label based upon the meaning label, and the meaning label extracted in a pair with the evaluation expression. |