Requirements for Multimodal Wizard of Oz Platforms

The Wizard of Oz (WOz) technique is a mechanism for the experimental evaluation of user interfaces. It allows the observation of a user operating an apparently fully functioning system whose missing services are supplemented by a hidden wizard. From our analysis of existing WOz systems, we observe that this technique has primarily been used to study natural language interfaces. With recent advances in interactive media, multimodal user interfaces are becoming popular but our current understanding on how to design such systems is still primitive. In the absence of generalizable theories and models, the WOz technique is an appropriate approach to the identification of sound design solutions. We show how it can be extended to the analysis of multimodal interfaces and we formulate a set of requirements for multimodal WOz platforms. The Neimo system is presented as an illustration of our early experience in the development of such platforms.