Skip to content
Journal article

Efficacy of effect size measures in logistic regression: An application for detecting DIF

G??mez-Benito J, Hidalgo M, Padilla J...(+3 more)

Methodology, vol. 5, issue 1 (2009) pp. 18-25

  • 20


    Mendeley users who have this article in their library.
  • 8


    Citations of this article.
  • N/A


    ScienceDirect users who have downloaded this article.
Sign in to save reference


Statistical techniques based on logistic regression (LR) are adequate for the detection of differential item functioning (DIF) in dichotomous items. Nevertheless, they return more false positives (FPs) than do other DIF detection techniques. This paper compares the efficacy of DIF detection using the LR significance test and the estimation of the effect size that these procedures provide using R² of Nagelkerke. The variables manipulated were different conditions of sample size, focal and reference group sample size ratio, amount of DIF, test length and percentage of test items with DIF. In addition, examinee responses were generated to simulate both uniform and nonuniform DIF (symmetric and asymmetric). In all cases, dichotomous response tests were used. The results show that the use of R² as a strategy for detecting DIF obtained lower correct detection percentages than those obtained from significance tests. Moreover, the LR significance test showed adequate control of FP rates, close to the nominal 5%, although the rate was slightly higher than the nominal 5% when the sample size was smaller. However, when the effect size measure was used to detect DIF, the FP rates were lower and

Author-supplied keywords

  • Differential item functioning
  • Effect size measure
  • Logistic regression analysis
  • R2 of Nagelkerke

Find this document

Get full text

Cite this document

Choose a citation style from the tabs below