Accuracy and Sensitivity of Coefficient Alpha and Its Alternatives with Unidimensional and Contaminated Scales

Autor/inn/en	Xiao, Leifeng; Hau, Kit-Tai
Titel	Accuracy and Sensitivity of Coefficient Alpha and Its Alternatives with Unidimensional and Contaminated Scales
Quelle	In: Applied Measurement in Education, 36 (2023) 1, S.31-44 (14 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Zusatzinformation	ORCID (Xiao, Leifeng) ORCID (Hau, Kit-Tai)
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0895-7347
DOI	10.1080/08957347.2023.2172016
Schlagwörter	Test Theory; Test Reliability; Factor Analysis; Test Length; Sample Size; Simulation; Test Bias; Accuracy; Measures (Individuals); True Scores + Suchen Sie Ihr Suchwort? Testtheorie; Testreliabilität; Faktorenanalyse; Simulation program; Simulationsprogramm; Testkritik; Messdaten
Abstract	We compared coefficient alpha with five alternatives (omega total, omega RT, omega h, GLB, and coefficient H) in two simulation studies. Results showed for unidimensional scales, (a) all indices except omega h performed similarly well for most conditions; (b) alpha is still good; (c) GLB and coefficient H overestimated reliability with small samples and short scales, and (d) sensitivity to scale quality reduced with longer scales. For contaminated scales, (a) all indices except omega h were reasonably unbiased with non-severe contamination; (b) alpha, omega total, and GLB were more sensitive in picking up contamination with shorter scales, whereas omega RT and omega h were not; and (c) coefficient H could not pick up contaminated items among high-quality items. For applied researchers, (a) supplementary information of scale characteristics helps choose the appropriate index; (b) comparing different scales with one golden standard is inappropriate; (c) omega h should not be used alone. (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2024/1/01