What can syntax-based MT learn from phrase-based MT

We compare and contrast the strengths and weaknesses of a syntax-based machine translation model with a phrase-based ma-chine translation model on several levels. We briefly describe each model, highlight-ing points where they differ. We include a quantitative comparison of the phrase pairs that each model has to work with, as well as the reasons why some phrase pairs are not learned by the syntax-based model. We then evaluate proposed improvements to the syntax-based extraction techniques in light of phrase pairs captured. We also compare the translation accuracy for all variations.