Disambiguating Rhetorical Structure

Empirical studies of text coherence often use tree-like structures in the spirit of Rhetorical Structure Theory (RST) as representational device. This paper identifies several sources of ambiguity in RST-inspired trees and argues that such structures are therefore not as explanatory as a text representation should be. As an alternative, an approach toward multi-level annotation (MLA) of texts is proposed, which separates the information into distinct levels of representation, in particular: referential structure, thematic structure, conjunctive relations, and intentional structure. Levels are conceptually built upon each other, and human annotators can produce them using a dedicated software environment. We argue that the resulting multi-level corpora are descriptively more adequate, and as a resource are more useful than RSTstyle treebanks.