Design And Implementation Of CAT System Based On Cognitive Diagnosis Theory

Cognitive diagnostic computerized adaptive testing is a new type of teaching and evaluation method based on cognitive orientation.In the traditional paper-pencil test,subjects are required to complete the same written questions without considering their different ability levels.Obviously,in the test,the written test scores can not be a good reflection of the subjects' ability.The computerized adaptive test is gradually getting into people's sight.It can adaptively select examination questions suitable for the subjects according to the ability level of the subjects.This test method can meet the needs of the people to examine the actual ability of the subjects.However,with the development of the times,the purpose of testing is not only to provide a score,but to provide teachers with the result of responding to the actual knowledge of the subjects,and at the same time,it can also provide guidance for further learning.Cognitive diagnosis theory arises at the historic moment.Combining teaching research,psychometrics and cognitive science,it has gradually become the new direction of computerized adaptive testing.Currently,most researches on computer adaptive testing with cognitive diagnosis are in the theoretical research stage.Although the theoretical models of cognitive diagnosis emerge in an endless stream,few of them can be widely applied in practice or in the system.In addition,most of the cognitive diagnosis models are only suitable for specific scenarios due to their own limitations,and the corresponding systems only have the capability of implementing one model,which is not suitable for large-scale application and promotion.On the basis of deeply studying and summarizing several classical cognitive diagnosis models commonly used in recent years,this thesis defines the formal structure of cognitive diagnosis and proposes a new cognitive diagnosis model-Integrated Model,based on the characteristics of classic models.Verification shows that the model has relatively good completeness and accuracy.At the same time,we only need to define and modify its parameters based on the comprehensive model,so that we can generate other new models.Therefore,this model has certain scalability,which makes it easier for researchers to carry out horizontal comparison to the model.Based on the formalized model definition proposed in this paper,a CD-CAT prototype system is designed and implemented,and four classical models and the integrated model we propose are implemented in the system to facilitate the verification of various models.The system can also provide researchers with an algorithm verification platform.Researchers can use the modules provided by the system to customize the new algorithm and verify them.