Motifs in Reconstructed RST Discourse Trees

Abstract

In line with the compositionality criterion and hierarchy principle of Rhetorical Structure Theory (RST), this study converts each tree in the RST Discourse Treebank into three trees with mere ultimate nodes being clauses, sentences and paragraphs, respectively. It examines the motifs of rhetorical relations along three taxonomies at the three granularity levels and also lengths of these motifs, and finds they observe the negative binomial distribution and positive negative binomial distribution respectively. The study demonstrates the applicability of RST relational analysis between same-level terminal units, which works with various granularities.

Acknowledgements

We are deeply indebted to Prof. Reinhard Köhler and Prof. Timothy Osborne for their helpful suggestions. Thanks also go to Zichen Huang, Degao Li, Beliankou, and Haiqi Wu, who helped with data for the research. This study was partly supported by the MOE Project of the Center for Linguistics and Applied Linguistics, Guangdong University of Foreign Studies.

Notes

1. For instance, English (Carlson, Marcu, & Okurowski, 2002), German (Stede, 2004), Portuguese (Pardo & Nunes, 2008) and Spanish (da Cunha, Torres-Moreno, & Sierra, 2011).