pwr (version 1.0)

pwr-package: 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

ll{ Package: pwr Type: Package Version: 1.0 Date: 2006-01-10 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 and pwr.2p2n.test : test for two proportions (ES=h) pwr.t.test : t tests 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)

References

J. Cohen (1988) Statistical power analysis for the behavioral scientist. 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="one.sided")

## Exercise 7.3 p. 251 from Cohen (1988)
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")