摘要 |
Provided are a related expression generation section that accepts an evaluation object expression, an linguistic expression to be evaluated, as input and generates a linguistic expression related to the evaluation object expression as a related expression; and a credibility calculation section that acquires the evaluation object expression and the related expression from a plurality of electronic documents along with time information and calculates credibility concerning the meaning of the evaluation object expression at a specific point in time by comparing the number of times that the acquired evaluation object expression appears and the number of times that the acquired related expression appears at the same time point. |