Abstract
Detecting differential item functioning through residual analysis: an irt applicatton. In this paper we present an IRT procedure for DIF detection through a program of residual analysis (RES.BAS) based on the Linn & Harnsich (1981) method of analizing residuals obtained when fitting data from the focal group to a previously determined model on a reference group. For estimating accuracy of this procedure, a comparison with four other methods Mantel-Haenszel, Lord`s test, log-lineal model and logistic regression- has been carried through a simulation study. Results show that both the proposed method and the logistic regression one, are superior to Mantel-Haenszel and slightly better than the log-lineal model. One of the main advantages of residual program is its capacity, not only to differentiate between uniform and no uniform DIF, but also in detecting direction, size and ability levels in which DIF is present.
