Reasoning about Algebraic Answers in Physics

One of the key components of an Intelligent Tutoring System (ITS) is the mechanism for reasoning about the student’s input. The impact of this component extends far beyond the presentation of the lesson material to the success of the system itself. It affects how precisely the system can pinpoint student errors and thus the subsequent help that the system provides. This paper describes an example of a class of Physics problems whose answers are most naturally represented as algebraic equations. We describe how our system, the PHYSICS-TUTOR, supports such a mechanism and the reasoning underlying it. Analyzing such input requires not only an understanding of algebra but also knowledge of physics concepts.