Discourse analysis and pragmatics in the design of a conversation prosthesis

The Microcomputer Centre at the University of Dundee is involved in developing communication devices for severely physically disabled non-speaking people. Existing communication systems are suitable for message-passing, but are inadequate for enabling an approximate form of real conversation. The authors have been working on a system which views a conversation in terms of pragmatics, and whose design is derived from this starting point. The system is called CHAT, which stands for Conversation Helped by Automatic Talk. To help a disabled person achieve continuity of conversation, The authors have designed CHAT to minimize the waiting time between utterances. It does this by giving speed of output a higher priority than precise control over every aspect of what is said. Another way CHAT increase the speed of output is to have the user prepare text in his own time, for outputting later at a faster rate, when the occasion is appropriate.