In the previous chapter we looked at some proposals about the types of cognitive operation that underlie semantic ability. In this chapter, we examine some attempts to formalize and model the conceptual representations involved in language. In 8.1 we examine Jackendoff's conceptual semantics, a theory about the cognitive structures behind language and the modes of their interaction. This is followed by a discussion of the treatment of meaning in computational linguistics, which uses computer models of language as an aid to understanding the mental processes involved in language production and understanding (8.2). We will concentrate on the aspects of computational linguistics which give insight into the nature of the task of meaning-processing. We specifically look at WordNet, an online lexical database, at the problems of word-sense disambiguation, and at Pustejovsky's solution to this in his model of qualia structure.