The Advantages of Using Planned Comparisons over Post Hoc Tests.

Autor/in	Kuehne, Carolyn C.
Titel	The Advantages of Using Planned Comparisons over Post Hoc Tests.
Quelle	(1993), (33 Seiten) PDF als Volltext kostenfreie Datei Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Monographie
Schlagwörter	Analysis of Variance; Comparative Analysis; Discriminant Analysis; Heuristics; Multivariate Analysis; Power (Statistics); Research Design; Research Methodology; Robustness (Statistics) + Suchen Sie Ihr Suchwort? Diskriminanzanalyse; Heuristik; Multivariate Analyse; Forschungsdesign; Research method; Forschungsmethode; Widerstandsfähigkeit
Abstract	There are advantages to using a priori or planned comparisons rather than omnibus multivariate analysis of variance (MANOVA) tests followed by post hoc or a posteriori testing. A small heuristic data set is used to illustrate these advantages. An omnibus MANOVA test was performed on the data followed by a post hoc test (discriminant analysis). A second MANOVA using Helmert coding as a means for a planned comparison test was run and the results were compared to those from the MANOVA followed by the unplanned tests. The results provide concrete examples of the different possible outcomes using various procedures. Two advantages of using planned or a priori contrast over post hoc tests are presented. In addition to increasing the power against Type II error rate, planned comparisons force the researcher to be more thoughtful in the design of the research. Nine tables and an appendix containing the questionnaire. (Contains 24 references.) (Author)
Erfasst von	ERIC (Education Resources Information Center), Washington, DC