Ramsay-Curve Differential Item Functioning

Autor/in	Woods, Carol M.
Titel	Ramsay-Curve Differential Item Functioning
Quelle	In: Applied Psychological Measurement, 35 (2011) 7, S.536-556 (21 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0146-6216
DOI	10.1177/0146621611417123
Schlagwörter	Simulation; Item Response Theory; Testing; Questionnaires; Interviews; Computation; Multiple Regression Analysis; Evaluation Methods; Statistical Bias; Test Bias; Maximum Likelihood Statistics; Error of Measurement; Test Results; Computer Software + Suchen Sie Ihr Suchwort? Simulation program; Simulationsprogramm; Item-Response-Theorie; Testdurchführung; Testen; Fragebogen; Interviewing; Interviewtechnik; Testkritik; Messfehler
Abstract	Differential item functioning (DIF) occurs when an item on a test, questionnaire, or interview has different measurement properties for one group of people versus another, irrespective of true group-mean differences on the constructs being measured. This article is focused on item response theory based likelihood ratio testing for DIF (IRT-LR or IRT-LR-DIF). Historically, the models have been fitted assuming the latent variables for both reference and focal groups are normal, but this is unnecessary. A new variation, called Ramsay-curve DIF (RC-DIF), is introduced here. In RC-DIF, the latent density for both groups is estimated simultaneously with the item parameters. Similar approaches in which the density for only one group is estimated, or the densities are estimated as empirical histograms (EHs), are also studied. Free software is available from the author to test each item individually for DIF with the latent densities estimated as EHs or RCs. A simulation study shows that these methods improve results compared with assuming normality mistakenly, and an empirical example illustrates the procedures. (Contains 5 figures, 6 tables, and 1 note.) (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10