Evaluation Methodologies for Intelligent Tutoring Systems

As intelligent tutoring system (ITS) issues are investigated and intelligent tutoring systems are developed, evaluation methodology becomes important. Basic researchers, system developers, and educators working with ITS all have motives for becoming involved in ITS evaluation. In formative evaluation, researchers examine a system under development, to identify problems and guide modifications. By contrast, summative evaluation is carried out to support formal claims about the construction, behaviour of, or outcomes associated with a completed system. Different methodologies are suitable for different types of evaluation, some focusing on internal considerations, such as architecture and behaviour, others on external considerations, such as educational impact. This paper draws upon the areas of intelligent tutoring systems research, expert systems design, computer-based instruction, education, and psychology to identify techniques for the formative and summative evaluation of ITS. Evaluation techniques are discussed in terms of the motivations for using them, situations for which they are particularly suitable, and their strengths and weaknesses. Techniques are illustrated with reference to actual studies whenever possible.