note 21
Riva and IJsselsteijn make the following distinction between presences that media can generate. Physical Presence is triggered when one is immersed in Virtual Reality, Location Based Entertainment, Cinema, Painting or Television. Co-presence occurs when one is engaged in Shared Virtual Environments, Video conferencing of video phoning. Social presence takes place when people communicate via email, telephone, letters, online chats or Multi-User Dungeons. (IJsselsteijn & Riva 2003).