pwr-package {pwr}R Documentation

Basic power calculations pwr

Description

Power calculations along the lines of Cohen (1988) using in particular the same notations for effect sizes. Examples from the book are given.

Details

Package: pwr
Type: Package
Version: 1.1
Date: 2007-01-31
License: GPL version 2 or newer

This package contains functions for basic power calculations using effect sizes and notations from Cohen (1988) : pwr.p.test : test for one proportion (ES=h) pwr.2p.test : test for two proportions (ES=h) pwr.t.test : t tests for means (ES=d) pwr.t2n.test : two samples (different sizes) t test for means (ES=d) pwr.anova.test : test for one-way balanced anova (ES=f) pwr.r.test : correlation test (ES=r) pwr.chisq.test : Chi-squared test (ES=w) pwr.f2.test : test for the general linear model (ES=f2)

Author(s)

Stéphane Champely (based on previous works by Claus Ekstrom and Peter Dalgaard)

Maintainer: Stéphane Champely <champely@univ-lyon1.fr>

References

J. Cohen (1988) Statistical power analysis for the behavioral sciences. Lawrence Erlbaum Associates, publishers.

Examples

## Exercise 8.1 P. 357 from Cohen (1988) 
pwr.anova.test(f=0.28,k=4,n=20,sig.level=0.05)

## Exercise 6.1 p. 198 from Cohen (1988)
pwr.2p.test(h=0.3,n=80,sig.level=0.05,alternative="greater")

## Exercise 7.3 p. 251
pwr.chisq.test(w=0.346,df=(2-1)*(3-1),N=140,sig.level=0.01)

## Exercise 6.5 p. 203 from Cohen (1988)
pwr.p.test(h=0.2,n=60,sig.level=0.05,alternative="two.sided")

[Package pwr version 1.1 Index]