In many fields of research including Education, Psychology, Social Science, and Marketing Research, data is generally collected through a questionnaire, which is often referred to as the survey instrument. For the scale development of these questionnaires two different approaches, Classical Test Theory and Item Response Theory, are mostly prevalent. In our study a comparison is made between these two theories by the means of item parameters as well as person parameters. Guttman scaling is selected for the classical test theory, whereas one and two parameter models are used for the item response theory. Our data consists of an instrument containing 64 items assessing the adolescent life of hardcore criminals, petty criminals, and community persons. The study reveals that the difficulty parameters of classical test theory are highly negatively correlated with one parameter model of item response theory whereas the discrimination parameters of Classical test theory and two parameter model of Item response theory are uncorrelated. The present study also reveals that the person parameters of classical test theory, and parameters under two models of Item response theory are highly positively correlated.
Keywords: Classical test theory, Item response theory, Item parameters, Person parameters.
Agarwal, G.G., & Asthana, A. (2022). Comparison of Classical Test Theory and Item Response theory in the Discrimination of Hard Core and Petty Criminals. Journal of Applied Statistics and Machine Learning. 1(1): pp. 113