Discourse analysis is the linguistics level that deals with language units of maximal size - from clause and sentences to paragraphs and whole text. During discourse analysis the text is often represented as a hierarchical tree with its parts connected by various rhetorical relations.There are different approaches to discourse analysis.
One of the most famous is the - Rhetorical Structure Theory (RST). It represents text as a hierarchy of elementary discourse units (EDUs) and describes relations between them and between bigger parts of text. Some EDUs are more essential and carry more important information (nucleus) than others (satellite). There are two rhetorical relation types: nucleus-satellite and multinuclear. While the first type connects a nucleus and a satellite (Elaboration, Background, Evidence), the latter includes EDUs that are equally important in the analysed discourse (Contrast, Restatement). The set of rhetorical relations can vary.
There are two rhetorical relation types: nucleus-satellite and multinuclear. Nucleus-Satellite connects a nucleus and a satellite (Elaboration, Background, Evidence). Multinuclear includes EDUs that are equally important in the analysed discourse (Contrast, Restatement). The set of rhetorical relations can vary. Sets of rhetorical relations can vary: the initial set proposed by Mann and Thompson consists of 23 relation types, but later modifications can contain up to 80 relation types, as in [Carlson, Marcu 2001].