The quality of an intelligent tutoring system is measured in terms of the speed and efficiency of learning. Many elements can improve this quality. If we consider the example of classical learning strategies, it is clear that they are not sufficient because the learner needs to be more involved in the learning session. Thus, there is a need for new co-operative learning strategies. For these strategies to be effective we need to be able to measure the weaknesses of the learner, and more specifically the discord in his or her ideas (internal conflict), in order to know which strategy is most suitable, when to use it, and what concepts need to be emphasised. Using the theory of cognitive-dissonance (discord between ideas), we have determined an indicator that measures the discord between the understanding of two elements of knowledge. To do this we have used the learning-by-disturbing strategy to test the confidence of the learner with regards to these units of knowledge and to make the learner aware of potential internal conflicts. We have developed a method allowing the detection of discordant concepts and the measure of dissonance rate. We also have shown that the learning process is improved when the tutor knows, for each learner, which concepts to focus.

Intelligent tutoring systems, learning strategies, conflicts, cognitive-dissonance