构造具有认知诊断功能的计算机化自适应测验(Computerized Adaptive Testing,CAT),关键在于设计不同于传统CAT的选题策略。本文采用先认知诊断后估计能力的方法,在诊断阶段用状态转换图描述特定认知领域中所有知识状态及这些状态之间的联系,以图的深度优先搜索方法为基础设计选题策略;而在能力估计精细化阶段,每个被试所测项目,不仅与其能力估计值相匹配,且只与其所掌握的属性相关。本文采用蒙特卡罗模拟针对三种不同的属性结构进行试验,结果良好。
An increased attention paid to "cogoitive bugs behavior," appears to lead to an increased research interests in diagoostic testing based on Item Response Theory ( IRT ) that combines cogoitive psychology and psychometrics. The study of cogoitive diagoosis were applied mainly to Paper - and - Pencil (P&P) testing. Rarely has it been applied to computerized adaptive testing (CAT). To our knowledge, no research on CAT with cogoitive diagoosis has been conducted in China. Since CAT is more efficient and accurate than P&P testing, there is important to develop an application technique for cogoitive diagoosis suitable for CAT. This study attempts to construct a preliminary CAT system for cognitive diagnosis. With the help of the methods for " Diagoosis first, Ability estimation second ", the knowledge state conversion diagram was used to describe all the possible knowledge states in a domain of interest and the relation among the knowledge states at the diagoosis stage, where a new strategy of item selection based - on the algorithm of Depth First Search was proposed. On the other hand, those items that contain attributes which the examinee has not mastered were removed in ability estimation. At the stage of accurate ability estimation, all the items answered by each examinee not only matched his/her ability estimated value, but also were limited to those items whose attributes have been mastered by the examinee. We used Monte Carlo Simulation to simulate all the data of the three different structures of cognitive attributes in this study. These structures were tree - shaped, forest - shaped, and some isolated vertices (that are related to simple Q - matrix). Both tree - shaped and isolated vertices structure were derived from actual cases, while forest - shaped structure was a generalized simulation. 3000 examinees and 3000 items were simulated in the experiment of tree - shaped, 2550 examinees and 3100 items in forest - shaped, and 2000 examinees and 2500 items in isolated vertices.