The research unit Language, Knowledge & Formalisation is centered on the important interaction between computer science and theory of language. What is here termed theory of language involves and draws on linguistics, philosophy of language, logic, rhetoric, narratology and issues in knowledge representation. Seen in combination with computer science this gives rise to four major fields of research in our area:

• Computational modelling of natural language
  
  
• Knowledge representation formalisms based on concepts and structures found in natural language
  
  
• Rhetorical and pragmatic theories about effective communication
  
  
• The foundational questions on the relationship between formal and natural languages

The first point is a branch of linguistics and hence devoted to the empirical facts of natural language.

The next two points are more abstract: they are not primarily concerned with working towards an empirically correct description of natural language. Rather, they deal with the question of how to structure and represent knowledge for a specific purpose - that is, formalisation - and how to communicate such formalisation in a rhetorically effective way. In this connection it is worth noting that even the pivotal computer science subject of programming languages has a substantial basis in theory of natural language in the sense just described. For example, fields such a logic programming and object orientation have an obvious background in the analysis of natural language and in conceptual systems which such analysis has brought forth (logic, categorisation and ontologies are cases in point).

The final point is of an epistemological nature: what is formalisation, and what happens when a formal representation of some segment of knowledge is made? To what extent have we here to do with the discovery of structures inherent in language, that is, an essentially descriptive endeavour? And to what extent should we rather think of formalisation as the invention of suitable or purposeful but not necessarily inherent structures, that is, a prescriptive endeavour?