Using R to Detect Differential Item Functioning: Science sub-test of Secondary School Entrance Examination

Differential Item Functioning (DIF) analyses provide critical information about validity of a test. R; an open source software, that comprises all of the DIF detection methods, has an important role in DIF research. Therefore, conducting a guiding study for measurement invariance or DIF analyses by following scientific methods and procedures will be very useful for researchers and practitioners. In this research, it is aimed to illustrate the procedures followed in different DIF detection methods in R, beginning from the installation of the R software to the interpretation of the analysis results, using a sample test (science sub-test of Secondary School Entrance Examination) and data. Four DIF detection methods, which are commonly used in DIF analyses, Mantel-Haenszel, Logistic Regression, SIBTEST and Likelihood Ratio methods are handled in this study. According to the analysis results, no items indicate DIF or indicate negligible DIF.