First, it cannot handle the unseen language problem: if an IGT in the test data belongs to a language that does not appear in the training data, this approach cannot classify it correctly.
in order to take advantage of the context information, we trained several classifiers (e.g., decision tree, Naive Bayes, and maximum entropy) using the Mallet package (McCallum, 2002) and a SVM classifier using the libSVM package (Chang and Lin, 2001).