Presupposition accommodation: a plea for common sense

Life is short. There is not enough time to explain everything. As speakers, or writers, we are forced to make assumptions. It is common to be advised to fix in one’s mind a picture of the audience, that is, to make an advance decision as to what the audience can be expected to know. Often, especially given limitations of time for speaking or space for writing, one is forced to take much for granted. As a result, cases of presupposition failure, the situation occurring when the speaker or writer takes for granted something of which the hearer or reader is not previously aware, are surely common. Somehow, hearers and readers cope, and usually without complaining. The author, in most genres, assumes that the text will be read linearly, and further assumes, optimistically, that readers will gather information throughout the reading process. So what the author has is not a fixed picture of the common ground with the intended readership, but a rather rough cut and idealized movie of how this common ground should develop. Each frame in the movie approximates what is common between relevant aspects of (1) the author’s beliefs at time of writing, and (2) the readers’ beliefs as they reach some point in the text. At risk of straining the cinematic metaphor somewhat, it could be said that the text itself is analogous to a script, but with detailed screenplay and directorial instructions omitted. Barring a major scientific breakthrough, the corresponding film will never be put on general release, so precisely how the writer intends the information state of idealized readers to evolve as they read is never made public in all its technicolor glory. In this paper, I will describe in brief a model of how readers’ information states do evolve, as they construct their own movies on the basis of the script.