pwr-package               package:pwr               R Documentation

_B_a_s_i_c _p_o_w_e_r _c_a_l_c_u_l_a_t_i_o_n_s 
_p_w_r

_D_e_s_c_r_i_p_t_i_o_n:

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

_D_e_t_a_i_l_s:


       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)

_A_u_t_h_o_r(_s):

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

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

_R_e_f_e_r_e_n_c_e_s:

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

_E_x_a_m_p_l_e_s:

     ## 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")

