Abstract:

Cognitive diagnosis models (CDMs) are one family of psychometric models developed primarily for assessing examinees’ mastery and non-mastery of skills or attributes. The extent to which the cognitive diagnosis models’ hypotheses fit the real response patterns substantially influences the validity of cognitive diagnostic evaluation. The model-data fit tests in cognitive diagnostic theory are typically based on the item fit tests, the overall fit tests and the person fit tests. Comprehensive and structural introduction and evaluation of the model-data fit test methods and related statistics are intended to aid the future cognitive diagnostic studies and practice. Directions of future researches on model-data fit for cognitive diagnosis models include further inspection of the evaluation and comparison of fit test statistics under more complex simulation conditions, the improvement of the existing fit statistics and the development of novel fit statistics.

Key words: cognitive diagnostic models, test of model-data fit, item fit, overall fit, person fit