Research on student modelling and problem generation for intelligent CAI systems

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This project aims to realize highly individualized dialogue. In order to achieve the purpose, we studied following four themes.1) Conceptual model of Intelligent CAI:In order to make mixed initiative and highly individualization feasible, it is necessary for an ICAI system not only to recognize the purpose of tutoring and to solve unexpected problems but also to understand student's requirements, student's method of problem solving and dialogue context. In order to fulfill the above requirements, we proposed a conceptual model of a dialogue system called "dual model".2) Knowledge representation model: We proposed a multi-hierarchical knowledge representation model to implement the dual model. In this model, two kinds of relationship for knowledge inheritance are provided; natural implication relations and strategy graph. The strategy graph divides all courseware knowledge into small worlds according to the tutoring sequence of worlds. The introduction of the strategy graph results the following two features. First, students can easily understand the material by studying it step by step along the strategy graph. Second, the strategy graph contributes to reduce the search spece when the system identifies student's error origins.3) Student model: We proposed a method called " perturbation method" to identify student's error origins. Many of students' error are considered to originate from commonly observed behaviors which are independent from courseware materials; those behaviors include remembering wrong facts, applying some methods of problem solving incorrectly, mixing newly studied knowledge with formerly studied one, etc. Corresponding to these erroneous behaviors, our method generates hypotheses against student's erroneous knowledge by perturbing correct knowledge. The identified error origins are accumulated into each student's model.4) Pedagogical dialogue: We studied on methods of generating questions,pedagogical remediation and answering student's questions.