Reasoning With Worlds and Truth Maintenance In An Intelligent Tutoring System

One of the distinguishing features of Intelligent Tutoring Systems (ITS), and a winning point over traditional Computer-aided Instruction (CAI) systems, is that ITSs are endowed with problem-solving capabilities in the domain to be taught. In this article, we describe the use we have made of a particular inferential mechanism, based on a context system associated with a truth maintenance syste, for building an expert system in education. In particular, we present the use of such tools in the design of the expert module of SAMPLE, an ITS for teaching high school and college students how to analyze electrical circuits in alternate current in a steady condition. We stress the capability of the system of determining all the possible solutions to a given problem even if it is proposed by a student.