S. argues that conversation does not have a (intristic) structure which can be captured in a theory comparable to the way in which speech acts are captured by speech act theory, and that it is not subject to constitutive rules. He then discusses two notions which are fundamental to understanding conversation: `shared intentionality', which specifies conversation in the domain of text types, and `back ground', which is needed for the interpretation of conversational sequences. This paper is an elaborated version of J. R. Searle (1986): `Introductory essay: Notes on conversation'.