Abstract: A discourse context is identified with the set of possible worlds that represents the shared information that is available to the participants in the discourse for the interpretation of speech acts. Two ways in which a speech act changes the context are distinguished. The notion of accommodation is examined, and a problem about this representation of context, raised by Hans Kamp, is addressed. The apparatus developed is applied to some problems about indefinite reference and anaphoric pronouns.

Keywords: accommodation, anaphoric pronoun, discourse context, indefinite reference, possible world, speech act,