Many examples of computer-based learning related to interactive storytelling have been developed, both for commercial and educational purposes. These range from a simple level of interaction (e.g. Living Books by Broderbund Software) where the user has no control of the outcome, to the level where children collaborate to form the outcome[Steiner, 1995, Steiner & Moher, 1992, Steiner & Moher, 1994]. These examples have been developed mainly for two-dimensional display environments, thus lacking the immersive qualities of a VR environment.
More elaborate models, primarily research oriented, are efforts such as the Oz Project[Bates, 1992], where the focus is on creating believable agents with emotions, or Laurel's Interactive Fantasy system[Laurel, 1991]. The UNIVERSE system[Lebowitz, 1984] deals with narrative, characters, and coherent plot structures, while the Virtual Theater group at Stanford investigates these areas in relation to children. Seymour Papert's Epistemology and Learning Group at MIT works primarily around the idea of constructionism, building systems based on Legos(tm) and other construction kits[Papert, 1991]. HITL researchers at the University of Washington address educational issues in VR at a more theoretical level. Finally, there are the text-based virtual communities of MUDs (Multi-User Dungeon) and MOOs (MUD Object-Oriented) that follow narrative structures, but lack the immersion provided by 3D graphical VR systems.
Some of these projects are research tools and do not directly address educational issues, while others remain at a theoretical level. Our work integrates concepts from these projects but also attempts to extend the above efforts into a complete environment that shares common characteristics. It uses immersion to provide a natural and familiar style of interaction; creates a basis for collaboration and construction in the environment; sustains a narrative as a basis for coherency.