The Textual Development Of Non-Stereotypic Concepts

In this paper the text theoretical foundation of our text analysis system KONTEXT is described. The basic premise of the KONTEXT model is that new concepts are communicated by using the mechanisms of text constitution. The text model used assumes that the information conveyed in a text and the information describing its contextual organization can be structured into five layers (sentence structure, information on thematic progression, referential structure, conceptual representation of the text and conceptual background knowledge). The text analysis component constructs and traverses the information of these layers under control of the discourse development. In this way, it can incrementally construct a textual view on knowledge, rather than only recognizing precoded concepts. 1 I N T R O D U C T I O N In the field ofknowledge-bMed text analysis it has been regarded as insufficient to analyze a text against the background of static and stereotypic default assumptions for some time (cf. [Hellwig84], [Scha/Bruce/Polanyi87]). By applying this method the pre--coded concepts are invoked again and again during the process of text analysis, regardless of the changes land the new concepts being constituted by the ongoing text. The function of a text, however, is not confined to concept selection as in current knowledge-based applications. In addition, textual mechanisms are used to operate on concepts and to compose them to actual contexts, i.e. to constitute (new) concepts. Textually the contexts are established by the thematic and by the referential structure. Thus, new mechanisms are required which permit the textual organization to control the creation and manipulation of concepts in text processing. In a way, this is to tie linguistic and knowledge,-based approaches to text processing together into a single method. 2 T H E K O N T E X T M O D E L The basic premise of the KONTEXT model is that the relationship of expression and concept are changed during a text and concepts are communicated by using the mechanisms of text constitution. The KONTEXT model is based on the assumption that • the information conveyed in a text and the information describing its contextual organization can be structured into five layers. They define the sentence structure, information on thematic progression, the referential structure, the conceptual representation of the text and the conceptual background knowledge; • discourse provides the basic mechanisms by which concepts are constructed. Discourse is defined as sequences of transitions between discourse states and discourse states are defined by the information represented