A Power Formula for the Crossing Simultaneous Item Bias Test (SIBTEST) for Non-Uniform and Uniform Differential Item Functioning

• In Event: Roundtable Session 6
  In Roundtable Session: Differential Item Functioning: Methods and Applications

Abstract

In this paper we derive a power formula of the Crossing SIBTEST (CSIB) for the differential item functioning (DIF). Crossing SIBTEST is a popular method for detecting both non-uniform and uniform differential item functioning (DIF) effects. As shown in the derived formula, the asymptotic power is related to the sample size, effect size of DIF, the item response function (IRF) and the distribution of the latent trait of the reference and the focal groups. A Monte Carlo simulation study shows that the theoretical values calculated from the formulas derived in the paper are close to what are observed in the simulated data.

Author

• Zhushan Mandy Li, Boston College