A considerable amount of work in current AI research is concerned with inferring intentions from utterances (., [Allen 83], [Carberry 83], [Grosz, Sidner 86]) or planning speech acts serving certain goals (., [Appelt 85]), but only a few uniform approaches to both aspects have been presented. Most approaches to dialog control described in the literature offer either rigid action schemata that enable the simulation of the desired behavior on the surface (but lack the necessary degree of flexibility, e. g., [Metzing 79]), or descriptive methods which may also include possible alternatives for the continuation of the dialog, but.
