Overlay student models

The overlay student model has been used in a number of Intelligent Tutoring Systems such as GUIDON. It is particularly appropriate when the teaching material can be represented as a prerequisite hierarchy.

Within this model the student’s knowledge is assumed to be a subset of the expert’s knowledge and the goal of tutoring is to enlarge this subset as shown in figure 1.04



Figure 1.04 : A representation of an overlay model showing the effects of tutoring.


This model assumes that the student will not learn anything that the expert does not know. Specifically it does not cater for misconceptions or bugs that the student may have or acquire during tutoring. A second issue with the overlay model is that there is no mechanism to differentiate between knowledge the student has not yet grasped and knowledge the student has not yet been exposed to which has implications for the tutoring strategy. The differential student model addresses this point.

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Authored by Serengul Smith

E-mail to: serengul1@mdx.ac.uk
School of Computing Science Middlesex University
Revised: September 1998