Ensemble system for Part-of-Speech tagging

The paper contains a description of the Felice-POS-Tagger and of its performance in Evalita 2009. Felice-POS-Tagger is an ensemble system that combines six different POS taggers. When evaluated on the official test set, the ensemble system outperforms each of the single tagger components and achieves the highest accuracy score in Evalita 2009 POS Closed Task. It is shown first that the errors made from the different taggers are complementary, and then how to use this complementary behavior to the POS tagger’s advantage.