2. Evaluating Multimodal Systems

As seen in the previous chapter, multimodal systems are well-established—at least in the research community studying HCI. But during the development process and—at the latest–once the system is built, methods for quantitative assessment are needed. In fact, as systems are usually meant to fullfill certain needs of, assist or even replace the human, the user’s perspective needs to be considered from the very start of conceiving a system. This approach of taking into account the potential user group and its characteristics has culminated in the user-centered or participatory design approach (Schuler and Namioka 1993), namely involving the user in the design process. Some accepted methods for user-centered design, such as the cognitive walkthrough, are discussed below, please refer to Vredenburg et al. (2002) for a survey of user-centered design practice.