1. A method of extracting an experience sentence from a blog document, comprising: generating a sentence classifier using a machine learning algorithm based on grammatical features; and classifying experience sentences that represent actual experiences of users and non-experience sentences that represent no experience in the blog document using the sentence classifier, wherein generating the sentence classifier includes extracting the grammatical features from given training data, and wherein extracting the grammatical features from the given training data includes extracting verb classes from the sentences.