A Novel Translation Framework Based on Rhetorical Structure Theory

Rhetorical structure theory (RST) is widely used for discourse understanding, which represents a discourse as a hierarchically semantic structure. In this paper, we propose a novel translation framework with the help of RST. In our framework, the translation process mainly includes three steps: 1) Source RST-tree acquisition: a source sentence is parsed into an RST tree; 2) Rule extraction: translation rules are extracted from the source tree and the target string via bilingual word alignment; 3) RST-based translation: the source RST-tree is translated with translation rules. Experiments on Chinese-to-English show that our RST-based approach achieves improvements of 2.3/0.77/1.43 BLEU points on NIST04/NIST05/CWMT2008 respectively.