On the Problem of 'aboutness' in Document Analysis

One of the most crucial problem areas of information science concerns the identification of what documents are 'about'. This paper seeks to define the notion of 'aboutness ' within the context of recent work in text linguistics. It describes, first, the essential communicational structures of sentences, paragraphs and texts in terms of theme, rheme and thematic progression, connectors of clauses and sentences, and semantic progression. It then identifies the basic features of the global structures of narrative and expository texts, describes the interaction of macroand microstructure in the interpretation of texts and the role of presupposed 'states of knowledge ' in both text production and text comprehension. Finally, it is argued that for the purposes of information systems the 'aboutness' of documents is to be found among the presuppositions of authors concerning the knowledge of their potential readers.