Outlines a theory of genres: of what they are, what they do, and what they explain. The central notion is that of a genre-for-a-community, which depends on psychological facts concerning tendencies of expectation in the audience. The minimal conditions for a genre to be instantiated are weak; Outlines some stronger conditions which allow us to focus on self-conscious genre-based effects. Suggests that genre, even thus strengthened, has only a very weak explanatory role. Gives accounts of genre identity across time, and of genre change.
Keywords: evolution, film, genre, literature, parallel distributive processing,