Some practical guidelines for effective sample size determination

RV Lenth - The american statistician, 2001 - Taylor & Francis
RV Lenth
The american statistician, 2001Taylor & Francis
Sample size determination is often an important step in planning a statistical study—and it is
usually a difficult one. Among the important hurdles to be surpassed, one must obtain an
estimate of one or more error variances and specify an effect size of importance. There is the
temptation to take some shortcuts. This article offers some suggestions for successful and
meaningful sample size determination. Also discussed is the possibility that sample size
may not be the main issue, that the real goal is to design a high-quality study. Finally …
Sample size determination is often an important step in planning a statistical study—and it is usually a difficult one. Among the important hurdles to be surpassed, one must obtain an estimate of one or more error variances and specify an effect size of importance. There is the temptation to take some shortcuts. This article offers some suggestions for successful and meaningful sample size determination. Also discussed is the possibility that sample size may not be the main issue, that the real goal is to design a high-quality study. Finally, criticism is made of some ill-advised shortcuts relating to power and sample size.
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