两种DIF检测方法的模拟研究

Simulation Study of Two Procedures for Detecting Differential Item Functioning

本研究通过Monte Carlo模拟,探讨MH和LR两种方法在检测DIF时I型错误率和检出率的情况。实验结果表明两种方法的I型错误均控制在0.05左右(α=0.05),LR方法的I型错误率呈现出更加稳定的状态。一致性DIF时,MH方法的检出率略高于LR方法;而非一致性DIF时,LR方法的检出率大大高于MH方法,MH方法对非一致性DIF不敏感。另外,两种方法一致性DIF的检出率随有DIF题目的比例增加而增加,而非一致性DIF的检出率随比例的增加而有所降低。

This study investigates the type I error rate and power of MH and LR procedures in detecting DIF.A simulation study shows that the type I error rates of these two procedures are close to the significance level （α=0.05）, and that of LR procedure turn out to be little more stable. When detecting uniform DIF, power of MH is little higher than LR’s;While detecting nonuniform DIF, LR’s power is much higher than MH’s. MH is not sensitive enough for nonuniform DIF. And power of these two procedures increases when the percentage of items containing DIF increases for uniform DIF, but decreases when the percentage increase for nonuniform DIF.