Integration of POStag-based Source Reordering into SMT Decoding by an Extended Search Graph
Josep Crego, José Bernardo Mariño Acebal · 2006
This paper presents a reordering frame-work for statistical machine translation (SMT) where source-side reorderings are integrated into SMT decoding, allowing for a highly constrained reordered search graph. The monotone search is extended by means of a set of reordering patterns (linguistically motivated rewrite patterns). Patterns are automatically learnt in train-ing from word-to-word alignments and source-side Part-Of-Speech (POS) tags. Traversing the extended search graph, the decoder evaluates every hypothesis making use of a group of widely used SMT models and helped by an addi-tional Ngram language model of source-side POS tags. Experiments are reported on the Euparl task (Spanish-to-English and English-to-Spanish). Results are presented regard-ing translation accuracy (using human and automatic evaluations) and computational efciency, showing signicant improve-ments in translation quality for both trans-lation directions at a very low computa-tional cost. 1