1. A method for classifying text, comprising the steps of: determining text features from the text; transforming the text features to topic features; determining scores from the topic features, wherein the determining steps use a model, wheren the model is a disciminative topic model comprising a classifier operating on the topic features, and the transforming is optimized to maximize the scores of a correct class relative to the scores of incorrect classes; and selecting a set of class labels with highest scores for the text, wherein the steps are performed in a processor.