Annotation upon Annotation: Adding Signalling Information to a Corpus of Discourse Relations

We present an annotation effort that involves adding a new layer of annotation to an existing corpus. We are interested in how rhetorical relations are signalled in discourse, and thus begin with a corpus already annotated for rhetorical relations, to which we add signalling information. We show that a very large number of relations carry signals that identify them as such. The detailed, extensive analysis of signals in the corpus will aid research in the automatic parsing of discourse relations.