lordif-package |
Logistic Ordinal Regression Differential Item Functioning using IRT |
Anxiety |
A Measure of Anxiety |
calcprob |
calculates item response probabilities |
calctheta |
calculates EAP theta estimates and associated standard errors |
collapse |
collapses response categories |
DFIT |
calculates DFIT statistics |
equate |
performs Stocking-Lord Equating |
extract |
extracts IRT item parameters |
getcutoff |
determines a cutoff threshold |
lordif |
performs Logistic Ordinal Regression Differential Item Functioning using IRT |
montecarlo |
performs Monte Carlo simulations to generate empirical distributions |
permute |
performs permutation test for empirical cutoff thresholds |
plot.lordif |
Plot method for lordif class |
plot.lordif.MC |
Plot method for Monte Carlo simulation output |
probgpcm |
calculates item response probabilities according to GPCM |
probgrm |
calculates item response probabilities according to GRM |
recode |
recodes item responses |
rundif |
runs ordinal logistic regression DIF |
runolr |
runs ordinal logistic regression models |
separate |
splits item response vectors of DIF items by group |
tcc |
computes a test characteristic curve (tcc) |