Nuclearity in RST and signals of coherence relations

Debopam Das


Abstract
We investigate the relationship between the notion of nuclearity as proposed in Rhetorical Structure Theory (RST) and the signalling of coherence relations. RST relations are categorized as either mononuclear (comprising a nucleus and a satellite span) or multinuclear (comprising two or more nuclei spans). We examine how mononuclear relations (e.g., Antithesis, Condition) and multinuclear relations (e.g., Contrast, List) are indicated by relational signals, more particularly by discourse markers (e.g., because, however, if, therefore). We conduct a corpus study, examining the distribution of either type of relations in the RST Discourse Treebank (Carlson et al., 2002) and the distribution of discourse markers for those relations in the RST Signalling Corpus (Das et al., 2015). Our results show that discourse markers are used more often to signal multinuclear relations than mononuclear relations. The findings also suggest a complex relationship between the relation types and syntactic categories of discourse markers (subordinating and coordinating conjunctions).
Anthology ID:
W19-2705
Volume:
Proceedings of the Workshop on Discourse Relation Parsing and Treebanking 2019
Month:
June
Year:
2019
Address:
Minneapolis, MN
Editors:
Amir Zeldes, Debopam Das, Erick Maziero Galani, Juliano Desiderato Antonio, Mikel Iruskieta
Venue:
NAACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
30–37
Language:
URL:
https://aclanthology.org/W19-2705
DOI:
10.18653/v1/W19-2705
Bibkey:
Cite (ACL):
Debopam Das. 2019. Nuclearity in RST and signals of coherence relations. In Proceedings of the Workshop on Discourse Relation Parsing and Treebanking 2019, pages 30–37, Minneapolis, MN. Association for Computational Linguistics.
Cite (Informal):
Nuclearity in RST and signals of coherence relations (Das, NAACL 2019)
Copy Citation:
PDF:
https://aclanthology.org/W19-2705.pdf