Signalling of Coherence Relations in Discourse
This project (also my PhD project) investigates how coherence relations are signalled in discourse, and what signals are used to indicate them. A secondary goal of this study is to examine whether coherence relations are more frequently explicit or implicit in terms of the type of signalling involved. I conducted a corpus study, examining the RST Discourse Treebank which includes a collection of 385 Wall Street Journal articles annotated for rhetorical (or coherence) relations. I examined each and every relation in that corpus, identifying the signals for those relations, and finally, adding a new layer of annotation to them, to include signalling information. Results from my corpus study show that the majority of relations (over 90%) in a discourse are signalled (sometimes by multiple signals), and also that the majority of signalled relations (over 80%) are indicated by signals other than discourse markers, such as lexical, semantic, syntactic and graphical features.