| 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) |