Intelligent tutoring and assessment built on an understanding of a technical problem-solving task

In this paper we describe Hydrive, an operational computer-based intelligent tutoring system built to help Air Force technicians develop generalizable skills for troubleshooting hydraulics systems. We use Hydrive as an example of how effective training and assessment is developed from a coherent understanding of a target task and how this understanding can be consistently represented in all aspects of a training/assessment instrument. We show how an organizing principle of expert behavior, active path analysis, is used to inform the design and content of the tutor's system, student and instructional models and the design of the tutor's interface. We conclude with information about Hydrive's field trial evaluation and some thoughts on knowledge acquisition and generalizability.