Brian A. Stone, James C. Lester
One of the most promising opportunities introduced by rapid advances in knowledge-based learning environments and multimedia technologies is the possibility of creating animated pedagogical agents. These agents should exhibit three properties: timely domain coverage (they should clearly communicate fundamental concepts and relationships within the allotted time); contextuality (they should provide explanations in appropriate problem-solving contexts); and continuity (their activities and utterances should be pedagogically, visually, and aurally coherent). We have developed the coherence-structured behavior space approach to creating animated pedagogical agents. This is a two-step approach. First, we design a behavior space of animation and audio segments that are structured by prerequisite relationships and a continuity metric. Second, we navigate coherent paths through the space to dynamically sequence behaviors. This creates seamless global behaviors that communicate fundamental knowledge and provide contextualized problem-solving advice. The coherence-structured behavior space approach has been implemented in Herman the Bug, an animated pedagogical agent for Design-A-Plant, a knowledge-based learning environment for botanical anatomy and physiology. Formative evaluations of the agent with middle school students are encouraging.