1. A method in a computer system for classifying a message of a discussion thread as a question or not a question, the method comprising: providing discussion threads having messages; generating feature vectors of messages of the provided discussion threads; providing classifications of messages of the provided discussion threads as questions or not questions; training a classifier using the generated feature vectors and provided classifications of messages of the provided discussion threads; and classifying a message of a discussion thread as a question or not a question using the trained classifier.