本文在0-1评分的CD-CAT基础上,拓展出了适合多级评分CD-CAT(ps CD-CAT)的认知诊断模型及选题策略,为实现多级评分CD-CAT提供了方法支持。Monte Carlo模拟实验结果表明:本文拓展的多级评分CD-CAT具有较理想的属性诊断正确率及测验效率和题库安全性,可以用于多级评分数据的CD-CAT;模拟实验还表明,整体来看PS-PWKL和PS-HKL两种选题策略具有较高属性判准率、题库安全性和高测验效率,且均优于PS-KL选题策略。总之,本研究对于进一步拓展CD-CAT在实践中的应用提供了认知诊断模型与选题策略等。
Cognitive diagnostic computerized adaptive testing(CD-CAT) purports to combine the strengths of both CAT and cognitive diagnosis. Currently, most CD-CAT researches focus on the dichotomous data. However there are large polytomous data in educational and psychological tests in practice. This paper proposed a new CD-CAT procedure with polytomous score, called as ps CD-CAT. The paper focused on two facets: one was to develop the item selection algorithm, parameter estimation, the polytomous cognitive diagnostic model and terminal rules for ps CD-CAT; the other one was to discuss the classification accuracy and item usage in ps CD-CAT. Monte Carlo simulation was conducted here. Two experimental conditions were simulated: the fixed test length CAT(10, 15 and 20 items respectively) and the variable test length CAT(the post probability of knowledge state was set to 0.75,0.80 and 0.85 respectively). Simulation studies showed: The classification accuracy, test security and test efficiency under ps CD-CAT were all acceptable and reasonable. Whenever under fixed or variable length conditions, PS-PWKL and PS-HKL item selection strategies had high classification accuracy, test security and test efficiency. However, PS-KL item selection strategy had low classification accuracy under fixed variable length conditions and had low test security and test efficiency under variable length conditions. Contract to the random item selection, PS-PWKL and PS-HKL algorithm should be improved to control the item exposure. In conclusion, the proposed ps CD-CAT by this paper had overcame the shortcomings stemmed from dichotomously scored CD-CAT, thus they might expect a good prospect and application. And it provided a kind of new methods and techniques in cognitive diagnosis, which might extended the applicable area.