Patent ID: 8606810

Claim:
An information analysis device comprising: a related expression generation section that accepts an evaluation object expression as input, the evaluation object expression being an linguistic expression to be evaluated, and generates a linguistic expression related to the evaluation object expression as a related expression; and a credibility calculation section that acquires occurrences of the evaluation object expression together with first time information indicating a time correlated to the occurrences of the evaluation object expression and occurrences of the related expression together with second time information indicating a time correlated to the occurrences of the related expression from a plurality of electronic documents and calculates credibility concerning the meaning of the evaluation object expression at a specific point in time at least on the basis of a first frequency that the acquired evaluation object expression appears in a term including the specific point of time and a second frequency that the acquired related expression appears in the same term including the same specific point of time, wherein the first frequency is obtained from pieces of said first time information, each of which is correlated to each of the occurrences of the evaluation object expression, and the second frequency is obtained from pieces of said second time information, each of which is correlated to each of the occurrences of the related expression.