Research In Cognitive Diagnosis In CAT Based On Graded Response Model

Computerized Adaptive Testing (CAT) is an important part of the computer assisted instruction and modern measurement research , the aim of CAT is to construct an optimal test for each examinee, this is realized by estimating the examinee's ability after administration of each item and selecting the next item based on the current ability estimate. However, the traditional CAT only gives a score to the examinee after the test. But the information about which aspects the examinees have mastered or have not can't be reported by the traditional CAT. Recently, the cognitive diagnosis has become one of important parts of research on CAT ,but most of the researches are based on dichotomous scoring model, the extent of which is not applied extensively.So the cognitive diagnosis under polychotomous scoring model is very meaningful.Cognitive diagnosis CAT based on Polychotomous Scoring Model has been researched and developed in this paper. the examinee's ability has been estimated after carrying out cognitive diagnosis under the Samejima Graded Response Model: the corresponding relationship between examinee's attribute mastery patterns and item'sattribute mastery patterns was taken into account. And examinee's response was dealt with weightedly. Then classify the examinees according to their response rector. The examinee's ability was estimated after confirming their cognitive situation. The CAT can't finish until the given amount of information was achieved. The results of this design indicate that accuracy of the CATs diagnosis is comparative higher andsteadier, the ability of evaluation was also more accurate and safer.The main creative points of this paper are: CAT based on Polychotomous Scoring Model has been researched and developedin this paper. The experimental results show that the examinee's ability of evaluation was more accurate and the CAT was safer.