Sample size and power calculations made simple.

Background: Sample size estimation is an important concern for researchers as guidelines must be adhered to for ethics committees, grant applications and publications. Studies may be underpowered (too few participants) or overpowered (too many participants) so it is important to achieve the correct...

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Detalles Bibliográficos
Publicado en:International Journal of Therapy & Rehabilitation Vol. 17; no. 1; pp. 10 - 15
Autor principal: McCrum-Gardner E
Formato: pictorial tables/charts Journal Article
Publicado: Mark Allen Holdings Limited Jan2010
Acceso en línea:Ver este registro en EBSCOhost
Descripción
Sumario:Background: Sample size estimation is an important concern for researchers as guidelines must be adhered to for ethics committees, grant applications and publications. Studies may be underpowered (too few participants) or overpowered (too many participants) so it is important to achieve the correct balance. Content: The process of sample size calculations, including relevant definitions, is explained and clear examples for different study designs are provided for illustration. A range of software packages and websites are discussed and evaluated. Conclusions: The information regarding sample sizes and statistical programs should be useful for researchers in order to perform sample size calculations for research projects.