Structure and function of sub-information in lecture discourse

1. Introduction This paper argues that some parts of a lecture discourse that are commonly disregarded fulfill their own important functions with regard to a subject or purpose of an informative discourse. The ultimate purpose of an informative discourse is to communicate information effectively. There are two general methods to convey information effectively: The first method is to use scientific function of language faithfully. The second method is to compose discourse around core information you wish to convey so that it has coherence. These are regarded as the basic methods of producing an informative discourse, but, on the other hand, they contain some dangers that they might mislead the informative discourse as if it should preclude emotional function and sub-information. Consequently, in order to accomplish the purpose of an informative discourse, we have to discover the essence of it observing and analyzing practical discourses. Up to now, research about the essence of informative discourse has centered chiefly on the structure ofèxpository text'. For example, Brinker(1992; translated by Sung-man Lee 1994) analyzed on the level of proposition. He argued that the developing structure of expository text is composed of a combination of initial condition with rule statements explaining the object. However, the text used in his analysis can't explain what to discover in this paper because it has a high coherence relatively and it is a short text so we don't see the whole aspects of sub-information in it. Yeol-kyue Kim et al(1994) have discovered features of persuasive, argumentative, and expository text by focusing on content structure and grammar. In the case of expository text, the side of content structure relies on Brinker, and the side of grammar relies on coherence theory of general text linguistics. Sam-hyeong Lee(1994) analyzed the content structure of expository text regarding a principle permitting coherence of text as`relationality'. The result is not so different from a way of explaining used in traditional rhetoric. Bong-soon Kim(1999) classified the comprising principle of core contents in expository text into three principles: the principle of inclusion, the principle of preference, and the principle of mutuality. But since her arguments focus on the construction of subject, they do not satisfy our curiosity about what kind of aspects and functions sub-information have. Most preceding in-depth analyses deal with written discourse, but since the frequency of sub-information, the focus of this paper, is low by nature, there might be some elements that have …