A Comparison of the Parametric Methods Based on the Item Response Theory in Determining Differential item and Test Functioning

Abstract

This study aims to compare parametric methods based on the item response theory in determining differential item and test functioning. To this end, it analyzes differential item and test functioning by using the comparison method for item parameters, the comparison method based on the likelihood ratio test, and the method to determine differential item and test functioning (DFIT) both at the item and test levels, and compares these three methods in terms of the data obtained. The study was conducted on the data on the Progress in International Reading Literacy 2001 (PIRLS-2001) tests. The results of the analyses indicated a differentiation between the results of differential item and test functioning, which were obtained using the methods in question