Statistical versus Substantive Dimensionality: The Effect of Distributional Differences on Dimensionality Assessment Using DIMTEST

Autor/inn/en	Walker, Cindy M.; Azen, Razia; Schmitt, Thomas
Titel	Statistical versus Substantive Dimensionality: The Effect of Distributional Differences on Dimensionality Assessment Using DIMTEST
Quelle	In: Educational and Psychological Measurement, 66 (2006) 5, S.721-738 (18 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0013-1644
DOI	10.1177/0013164405285907
Schlagwörter	Multidimensional Scaling; Item Response Theory; Comparative Testing; Statistical Analysis; Simulation; Nonparametric Statistics; Construct Validity; Item Analysis; Regression (Statistics); Mathematical Concepts + Suchen Sie Ihr Suchwort? Mehrdimensionale Analysis; Item-Response-Theorie; Statistische Analyse; Simulation program; Simulationsprogramm; Itemanalyse; Regression; Regressionsanalyse
Abstract	It is believed by some that most tests are multidimensional, meaning that they measure more than one underlying construct. The primary objective of this study is to illustrate how variations in the secondary ability distribution affect the statistical detection of dimensionality and to demonstrate the difference between substantive and statistical dimensionality. Given dichotomous data simulated to be multidimensional, this study shows how varying the ability distributions affects the results obtained from DIMTEST, a nonparametric statistical procedure based on the theory of essential unidimensionality. Results indicate that the power of DIMTEST decreased as the mean of the secondary ability distribution approached the extremes and/or as the standard deviation of the secondary ability distribution approached zero. This has important implications for both researchers and practitioners because although a test may measure additional dimensions from a substantive viewpoint, these dimensions may not be detected statistically. (Contains 3 tables and 3 figures.) (Author).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10