The paper gives a survey on three approaches of statistical machine translation and the evaluation methods used in smt , the basic idea of parallel grammar based approach is to build parallel grammars for source and target languages , which conform the same probabilistic distribution 摘要本文綜述了基于信源通道思想和基于最大熵思想的統(tǒng)計(jì)機(jī)器翻譯方法并介紹了統(tǒng)計(jì)機(jī)器翻譯的評(píng)測(cè)方法。