Power and the computation of sample size

Part of the Statistics and Computing book series (SCO)


A statistical test will not be able to detect a true difference if the sample size is too small compared with the magnitude of the difference. When designing experiments, the experimenter should try to ensure that a sufficient amount of data are collected to be reasonably sure that a difference of a specified size will be detected. R has methods for doing these calculations in the simple cases of comparing means using one- or two-sample t tests and comparing two proportions.


Power Calculation Paired Test True Difference Acceptance Region Noncentrality Parameter 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. Altman, D. G. (1991), Practical Statistics for Medical Research, Chapman & Hall, London.Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Department of BiostatisticsUniversity of CopenhagenCopenhagenDenmark

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