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.