Intelligent AAC Systems attempt to provide a communication system that can interpret input from the user in much the same way a familiar listener would. The COMPANSION system is a research demonstration prototype which "interprets" compressed input given by a user of a word based system into a full grammatical sentence. In developing a usable system from the prototype the needs of the user must be specified in well-defined ways.
This paper reports some preliminary observations from an experiment in which word board users interact with their therapist to tell a story from a picture book. The analysis compares the therapist's output with what could be achieved by a system like COMPANSION and discusses the necessary functionality for a second generation prototype as well as some of the potential difficulties that will be faced.