Virtual Teacher.(Technology Information)

An animated agent helps students grasp complex tasks

Some teachers consistently go the extra mile to make sure their students fully comprehend what they're being taught. STEVE is one of them. An autonomous, animated agent within a simulated environment, STEVE, whose name is an acronym for Soar Training Expert for Virtual Environments, was designed by researchers at the University of Southern California to teach physical tasks to students in a 3D virtual environment.

Because he is driven by a system that integrates methods from three primary research areas--intelligent tutoring systems, computer graphics, and agent architectures--STEVE embodies a unique set of capabilities.

The intelligent tutor in STEVE can answer such questions as "What should I do next?" and "Why?" His computer-animated persona can demonstrate actions within the virtual environment that previous-generation disembodied intelligent tutors could not, and he can use gaze and gestures to direct students' attention and guide them through the virtual world. Finally, his agent architecture allows STEVE to continually monitor the state of the virtual world and both maintain a plan for completing his current task and revise the plan to accommodate unexpected events.

STEVE's reason for being, according to Jeff Rickel, who developed the technology along with USC colleague W. Lewis Johnson, is to serve as a mentor to students trying to master certain tasks, such as operating complicated machinery. In such situations, says Rickel, "people need hands-on experience in a wide range of situations. They also need a mentor who can demonstrate procedures, answer questions, and monitor their performance."

Unfortunately, it is often impractical to provide such training on real equipment given resource and logistical constraints. Consequently, Rickel notes, "we are exploring the use of virtual reality, where training takes place in a 3D simulated mock-up of the student's work environment. And since mentors and teammates are often unavailable when the student needs them, we are developing STEVE as an autonomous, animated agent that can play these roles."

Although simple 2D simulated interfaces might be sufficient for certain training applications, 3D virtual worlds are more critical in situations where students must learn how to use perceptual cues to guide their actions, how to navigate around complex scenes, and how to perform tasks that require spatial motor skills. In such situations, the ability of an animated agent to cohabit the virtual world with students and demonstrate physical tasks is a far more effective teaching approach than simply trying to describe the task verbally or by showing a videotape of the process. "With an interactive demonstration from an animated agent, students can view the demonstrations from different perspectives and interrupt with questions, and the agent can demonstrate the task under a Wide variety of conditions," says Rickel.