Phrase Tagset Mapping for French and English Treebanks and Its Application in Machine Translation Evaluation

Many treebanks have been developed in recent years for different languages. But these treebanks usually employ different syntactic tag sets. This forms an obstacle for other researchers to take full advantages of them, especially when they undertake the multilingual research. To address this problem and to facilitate future research in unsupervised induction of syntactic structures, some researchers have developed a universal POS tag set. However, the disaccord problem of the phrase tag sets remains unsolved. Trying to bridge the phrase level tag sets of multilingual treebanks, this paper designs a phrase mapping between the French Treebank and the English Penn Treebank. Furthermore, one of the potential applications of this mapping work is explored in the machine translation evaluation task. This novel evaluation model developed without using reference translations yields promising results as compared to the state-of-the-art evaluation metrics.