A Model-Free Diagnostic for Single-Peakedness of Item Responses Using Ordered Conditional Means

Autor/inn/en	Polak, Marike; De Rooij, Mark; Heiser, Willem J.
Titel	A Model-Free Diagnostic for Single-Peakedness of Item Responses Using Ordered Conditional Means
Quelle	In: Multivariate Behavioral Research, 47 (2012) 5, S.743-770 (28 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0027-3171
DOI	10.1080/00273171.2012.715563
Schlagwörter	Item Response Theory; Measures (Individuals); Test Items; Item Analysis; Methods; Goodness of Fit; Personality Measures; Attitude Measures + Suchen Sie Ihr Suchwort? Item-Response-Theorie; Messdaten; Test content; Testaufgabe; Itemanalyse; Method; Methode
Abstract	In this article we propose a model-free diagnostic for single-peakedness (unimodality) of item responses. Presuming a unidimensional unfolding scale and a given item ordering, we approximate item response functions of all items based on ordered conditional means (OCM). The proposed OCM methodology is based on Thurstone & Chave's (1929) "criterion of irrelevance", which is a graphical, exploratory method for evaluating the "relevance" of dichotomous attitude items. We generalized this criterion to graded response items and quantified the relevance by fitting a unimodal smoother. The resulting goodness-of-fit was used to determine item fit and aggregated scale fit. Based on a simulation procedure, cutoff values were proposed for the measures of item fit. These cutoff values showed high power rates and acceptable Type I error rates. We present 2 applications of the OCM method. First, we apply the OCM method to personality data from the Developmental Profile; second, we analyze attitude data collected by Roberts and Laughlin (1996) concerning opinions of capital punishment. (Contains 1 footnote, 5 tables, and 4 figures.) (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10