Developments in technology have made it possible for speech output to be used in place of the more usual visual interface in both domestic and commercial devices. Speech can be used in situations where visual attention is occupied, such as when driving a car, or where a task is complex and traditional visual interfaces are not effective, such as programming a video recorder. Speech can also be employed in specialist adaptations for visually impaired people. However, the use of speech has not been universally successful, possibly because the speech interaction is poorly designed. Speech is fundamentally different from text, and a lot of the problems may arise due to simplified text-to-speech conversion. Design of Speech-based Devices considers the problems associated with speech interaction, and offers practical solutions.

Representations of humans in virtual environments are called Avatars. This book brings together work from a variety of relevant disciplines to detail how humans interact in computer-generated environments. It contains contributions from several key people in the field, including Microsoft Researchs Virtual World Group, and presents their findings in a way that is accessible to readers who are new to the field. Coverage details Internet-based virtual worlds that have been widely used by the public as well as networked VR systems that have been primarily used in pilot studies and research.