Progress on natural language interfaces can perhaps be stimulated or directed by imagining the ideal natural language system of the future. What features (or even design philosophies) should such a system have in order to become an integral part of our work environments? What scaled-down versions of these features might be possible in the near future in "simple service systems" [2]? These issues can be broken down into the following four questions: i. What are the significant features of the environment in which the system will reside? The system will be one participant in an intricate information network, depending.
