Guidelines for multimodal user interface design

This article discusses six main categories of guidelines and represents a preliminary effort to establish principles for multimodal interaction design. The article also describes how to design for the broadest range of users and contexts of use. For this, designers should become familiar with users' psychological characteristics, such as cognitive abilities, motivation, level of experience, domain and task characteristics and cultural background, as well as their physical attributes such as age, vision and hearing. An application will be valued and accepted if it can be used by a wide population and in more than one manner. Thus multimodal designs can aid in extending the range of potential users and uses, such as when redundancy of speech and keypad input enables an application to be used in dark or noisy environments. Designers should support the best modalities anticipated in changing environments.