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Three Statistical Testing Procedures in Logistic Regression: Their Performance in Differential Item Functioning (DIF) DIF

Paek, Insu
Publication Year:
Report Number:
ETS Research Report
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Subject/Key Words:
Differential Item Functioning (DIF), Mantel-Haenszel Procedure, Logistic Regression, Wald Test, Likelihood Ratio Test, Score Test


Three statistical testing procedures well-known in the maximum likelihood approach are the Wald, likelihood ratio (LR), and score tests. Although well-known, the application of these three testing procedures in the logistic regression method to investigate differential item function (DIF) has not been rigorously made yet. Employing a variety of simulation conditions, this research (a) assessed the three tests’ performance for DIF detection and (b) compared DIF detection in different DIF testing modes (targeted vs. general DIF testing). Simulation results showed small differences between the three tests and different testing modes. However, targeted DIF testing consistently performed better than general DIF testing; the three tests differed more in performance in general DIF testing and nonuniform DIF conditions than in targeted DIF testing and uniform DIF conditions; and the LR and score tests consistently performed better than the Wald test.

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