Supplemental Material

Chapter 2: Observed-Score Methods

Data Files

MCData.csv

LikertData.csv

MCData3Groups.csv

MixedData.csv

R Script Files

Delta Plot Method

deltaPlot DIF Analyses.R

Mantel-Haenszel Procedure

dfiMH DIF Analyses.R

difGMH DIF Analyses.R

MH Polytomous DIF.R

Standardization Procedure

difStd DIF Analyses.R

SMD DIF Analyses.R

Logistic Regression

DIF Logistic Regression Dichotomous.R

DIF Logistic Regression Mixed Format Test.R

DIF Logistic Regression More than 2 groups.R

DIF Logistic Regression Polytomous.R

SIBTEST

SIBTEST DIF Analyses.R

Chapter 3: Item Response Theory

Data Files

MixedFormat.dat

LikertData.dat

flexMIRT Input Files

MixedFormat.flexmirt

LikertData.flexmirt

Chapter 4: Methods Based on Item Response Theory

b-plot and a-plot Method

Item Parameter Files

MCDataRef3PL.par

MCDataFoc3PL.par

MixedDataReference.par

MixedDataFocal.par

LikertReference.par

LikertFocal.par

R Script File

Perform b- and a-plot DIF Method.R

Lord's Chi-Square

Item Parameter Files

MCDataRef3PL.par

MCDataFoc3PL.par

MixedDataReference.par

MixedDataFocal.par

LikertReference.par

LikertFocal.par

Chapter 2: Observed-Score Methods

Data Files

R Script Files

Delta Plot Method

Mantel-Haenszel Procedure

Standardization Procedure

Logistic Regression

SIBTEST

Chapter 3: Item Response Theory

Data Files

flexMIRT Input Files

Chapter 4: Methods Based on Item Response Theory

b-plot and a-plot Method

Item Parameter Files

R Script File

Lord's Chi-Square

Item Parameter Files

R Script File

Likelihood-Ratio Test

Data Files

IRTLRDIF Input Files

Raju's Area Measure

Item Parameter Files

R Script File

DFIT

Item Parameter Files

R Script File