Title: On Using a Pilot Sample Variance for Sample Size Determination in the Detection of Differences between Two Means: Power Consideration.
Abstract:The a priori determination of a proper sample size necessary to achieve
some specified power is an important problem encountered frequently in
practical studies. To establish the needed sample size ...The a priori determination of a proper sample size necessary to achieve
some specified power is an important problem encountered frequently in
practical studies. To establish the needed sample size for a two-sample t test,
researchers may conduct the power analysis by specifying scientifically
important values as the underlying population means while using a variance
estimate obtained from related research or pilot study. In order to take
account of the variability of sample variance, this article considers two
approaches to sample size determinations. One provides the sample size
required to guarantee with a given assurance probability that the actual
power exceeds the planned power. The other gives the necessary sample size
such that the expected power attains the designated power level. The
suggested paradigm of adjusted sample variance combines the existing
procedures into one unified framework. Numerical results are presented to
illustrate the usefulness and advantages of the proposed approaches that
accommodate the stochastic nature of the sample variance. More
importantly, supplementary computer programs are developed to aid the
usefulness and implementation of the suggested techniques. The exposition
helps to clarify discrepancy in the previous demonstration and to extend the
development of sample size methodology.Read More
Publication Year: 2013
Publication Date: 2013-01-24
Language: en
Type: article
Access and Citation
Cited By Count: 2
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