i) Reuters21578: A dataset consisting of 10788 news documents from 90 different categories; ii) 20N ewsgroups: A collection of 18828 newsgroup posts that are divided into 20 different newsgroups; iii) T M C: A dataset containing the air traffic reports provided by NASA, which includes 21519 training documents with 22 labels.
despite of superior performances, only the simplest priors are used in these models, i.e.