Item Response Theory and Modeling with Stata

ABSTRACT This software review discusses the capabilities of Stata to conduct item response theory modeling. The commands needed for fitting the popular one-, two-, and three-parameter logistic models are initially discussed. The procedure for testing the discrimination parameter equality in the one-parameter model is then outlined. The commands for fitting several polytomous models are subsequently indicated, as are those facilitating model comparison. Scoring of individual units of analysis with Stata’s item response theory module is next discussed, and various graphical features of this module are pointed out. The review concludes with an illustration example of using Stata for item response modeling on an empirical data set.