Analysis of the concept of redundancy concerning the design of multimodal combinations of output-elements

The tendency in user interface design is to support interaction styles that resemble our interaction with our natural environment. In practice, this has resulted in adaptive, multimodal user interfaces. Concerning output, designers are challenged to create interfaces with multimodal output elements in which single messages from a designer to a user are presented in multiple forms, i.e., redundancy can be used to support computer human interaction. Redundancy is a complicated phenomenon, especially in multimodal cases, in which it is attempted to express the same information in quite distinct coding systems. However, when properly analyzed, redundancy as a central concept in the design process provides an interesting approach to multimodal information presentation. The paper first surveys the possible connotations of the concept. Then, a functional definition for the needs of application design is outlined by defining the conceptual environment of the concept of redundancy