PENDING
Please predict whether this patent is acceptable.PATENT ABSTRACT: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for receiving a message authored by a user, determining, using a first classifier, that the message contains at least a first word describing positive or negative sentiment and, based thereon, extracting, using a first feature extractor, one or more features of the message, wherein each feature comprises a respective word or phrase in the message and a respective weight signifying a degree of positive or negative sentiment, and determining, using a second classifier that uses the extracted features as input, a score describing a degree of positive or negative sentiment of the message, wherein the first feature extractor was trained with a set of training messages that each was labeled as having positive or negative sentiment.