A Comparative Analysis of the Efficacy of Differential Item Functioning Detection for Dichotomously Scored Items among Logistic Regression, SIBTEST and Raschtree Methods

Abstract

A variety of statistical methods is available for detecting Differential Item Functioning (DIF) in the Rasch model. Most of these methods consist of two approaches. The first is based on the comparison of the item parametersestimate pre-specified groups of subjects. The second is based on a comparison between all possible groups of subjects, regardless of person covariates. The purpose of this research is to compare the efficiency of Differential Item Functioning (DIF) detection between three methods: (1) Logistic regression based on classical test theory; (2) SIBTEST based on item response theory and (3) Raschtree based on model-based recursive partitioning. Detection of DIF was collected through simulation. The first phase of the study revealed the advantages and disadvantages of these three methods from a literature review. The second phase of the research compared the efficiency of DIF detection using data simulation of four factors: type of item, number of DIF, test length and sample size.