Perceptual control and layered protocols in interface design: II. The general protocol grammar

Perceptual control theory (PCT) is a framework theory for psychology, based on the tenet "All behaviour is the control of perception." Layered protoco l theory (LPT) is PCT applied to the special case of communication between cooperating partners, each controlling their own perceptions and many level s of abstraction within a dialogue. This paper discusses some perceptual co ntrol processes that occur within a single dialogue level, in the form of a General Protocol Grammar that is asserted to be valid for every level of e very dialogue. A companion paper is concerned with LPT applied to the desig n and analysis of human-machine interfaces.