Understanding Power and Rules of Thumb for Determining Sample Sizes

eng TQMP Tutorials in Quantitative Methods for Psychology 1913-4126 2007-09-01 3 2 43 50 article Understanding Power and Rules of Thumb for Determining Sample Sizes Carmen R. Wilson Van Voorhis wilson.carm@uwlax.edu 1 Betsy L. Morgan bm@where.ca 1 University of Wisconsin-La Crosse This article addresses the definition of power and its relationship to Type I and Type II errors. We discuss the relationship of sample size and power. Finally, we offer statistical rules of thumb guiding the selection of sample sizes large enough for sufficient power to detecting differences, associations, chi-square, and factor analyses. http://www.tqmp.org/Content/vol03-2/p043/p043.pdf Statistics statistical power