... we regard as discourse markers and thus are to be included in the lexicon, and determining the lex- ical entries for these words. Finding the "right" set of discourse markers is ... understanding, discourse markers serve as cues for inferring the rhetorical or seman- tic structure of the text. In the approach pro- posed by Marcu [1997], for example, the pres- ence of discourse markers ... spans; for exam- ple, because, since, and for this reason are dif- ferent markers for causal relations. Discourse markers are a syntactically quite heterogeneous group of words, many of which...