• h r (G), number of translation rules used in G. • h d (G), structure-based score of G. For FDTs generated by phrase-based paradigms, it can be computed by distortion models; while for FDTs generated by syntax-based paradigms, it can be computed by either parsing models or syntactic LMs (Charniak et al., 2003).
from Table 1 we notice that with FDT-SLM integrated, only 0.2 BLEU improvements can be obtained.