Following , concurrency of processing and the fusion of input/output data are the two main features of a multimodal system. Consequently, Nigay and Coutaz took these features as the basis for their design space and classification method.
The design space has been defined along three
dimensions: Levels of abstraction, Use of
modalities, and Fusion. In order to keep the model as simple as possible,
the permitted values of each dimension have been limited. The result is
shown in figure 4.1
Figure 4.1 : The multi-feature system design space (Taken from )
The design space is then used for a classification scheme for multimodal systems. By introducing weighted features of a system, the location of it within the design space can easily be determined. This is useful in order to test the effect of different features and commands, thus ``measuring'' the usability of an interface.
The second part of the paper deals with data fusion and concurrent processing. Therefore, a multi agent architecture is introduced which will not be further reviewed here. For data fusion, three levels of fusion have been identified: