Investigating Different Theory-Based Differential Item Functioning Methods Under Different Scoring Situations

Abstract

This study intended to investigate theoperations of various theory-based Differential Item Functioning (DIF) methodsunder different scoring situations. In this context, data obtained fromconducting a Verbal Reasoning Skills Test (scored both in dichotomous andweighted scores) on 1593 individuals was examined via Mantel-Haenszel/Mantel,Standardization and Likelihood Ratio Test techniques and items that point toDIF and numbers of items with DIF for each technique and scoring situation wereidentified. Results show that Classical Test Theory (CTT) based DIF methodsgenerally provided results that were consistent in themselves and that theseresults were not significantly different from each other. Agreement betweentechniques based on Item Response Theory (IRT) and Classical Test Theory (CTT)was found to be low under different scoring situations and results weresignificantly different from each other.

Keywords

• item scoring
• differential item functioning
• dif
• item bias
• bias
• mantel-haenszel
• likelihood ratio test
• item scoring
• differential item functioning
• dif
• item bias
• bias
• mantel-haenszel
• likelihood ratio test