A Note on a Relationship between Covariance Matrices and Consistently Estimated Variance Components. ACT Research Report Series 95-2.

Autor/in	Woodruff, David J.
Institution	American Coll. Testing Program, Iowa City, IA.
Titel	A Note on a Relationship between Covariance Matrices and Consistently Estimated Variance Components. ACT Research Report Series 95-2.
Quelle	(1995), (13 Seiten) PDF als Volltext kostenfreie Datei Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Monographie
Schlagwörter	Analysis of Variance; Estimation (Mathematics); Matrices; Test Items + Suchen Sie Ihr Suchwort? Estimation; Mathematics; Schätzung; Matrizenrechnung; Test content; Testaufgabe
Abstract	The one observation per cell two-way items by examinees random effects analysis of variance (ANOVA) with all error components zero is considered. The estimated variance components are expressed as functions of the inter-item covariance matrix and the inter-examinee covariance matrix. These expressions show that under the random effects model if the inter-item and inter-examinee covariance matrices are unconstrained then both the number of items and the number of examinees must approach infinity for the estimates of any of the variance components to be consistent. However, if these two covariance matrices are constrained so that each has homogeneous variances and convariances, then consistent estimates of the variance components can be obtained without both the number of items and the number of examinees simultaneously approaching infinity. (Contains seven references.) (Author)
Anmerkungen	ACT Research Report Series, P.O. Box 168, Iowa City, IA 52243.
Erfasst von	ERIC (Education Resources Information Center), Washington, DC