Comparing Treatment and Control Groups on Multiple Outcomes: Robust Procedures for Testing a Directional Alternative Hypothesis

Autor/inn/en	Lix, Lisa M.; Deering, Kathleen N.; Fouladi, Rachel T.; Manivong, Phongsack
Titel	Comparing Treatment and Control Groups on Multiple Outcomes: Robust Procedures for Testing a Directional Alternative Hypothesis
Quelle	In: Educational and Psychological Measurement, 69 (2009) 2, S.198-215 (18 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0013-1644
DOI	10.1177/0013164408322027
Schlagwörter	Control Groups; Experimental Groups; Outcomes of Treatment; Comparative Analysis; Testing; Statistical Analysis; Monte Carlo Methods + Suchen Sie Ihr Suchwort? Testdurchführung; Testen; Statistische Analyse; Monte-Carlo-Methode
Abstract	This study considers the problem of testing the difference between treatment and control groups on m [greater than or equal to] 2 measures when it is assumed a priori that the treatment group will perform better than the control group on all measures. Two procedures are investigated that do not rest on the assumptions of covariance homogeneity or multivariate normality: a likelihood ratio test based on a bootstrap critical value and a composite step-down procedure based on trimmed means. Type I error rates of both procedures are insensitive to assumption violations. Procedures that test a directional alternative hypothesis can be substantially more powerful than a procedure that tests a nondirectional hypothesis for certain configurations of the population mean vectors. The differences in average power of the investigated procedures are a function of the configuration of the population means, the magnitude of correlation among the outcome measures, and the shape of the population distribution. (Contains 4 tables.) (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10