Childpsy

Goal: Using GPower to compute the sample size needed

1. Download GPower by visiting this web site: http://www.gpower.hhu.de 
   [pic 1][pic 2][pic 3][pic 4]
2. Extract the GPower folder
3. Double-click the “GPowerSetup.msi” to install the GPower

• Sample size for two-tailed one-sample t-test

[pic 5][pic 6][pic 7][pic 8][pic 9][pic 10][pic 11][pic 12][pic 13][pic 14][pic 15][pic 16][pic 17][pic 18][pic 19]

• Input basic information by pressing the “Determine” button to calculate the effect size

[pic 20][pic 21][pic 22][pic 23][pic 24][pic 25][pic 26][pic 27][pic 28][pic 29]

• Sample size for two-tailed paired-samples t-test

[pic 30][pic 31]

• Again, you can input basic information by pressing the “Determine” button to calculate the effect size

[pic 32][pic 33]

• Sample size for two-tailed independent-samples t-test

[pic 34][pic 35][pic 36][pic 37]

• Again, you can input basic information by pressing the “Determine” button to calculate the effect size

[pic 38][pic 39]

• Sample size for one-way ANOVA with three groups

[pic 40][pic 41][pic 42]

• Again, you can input basic information by pressing the “Determine” button to calculate the effect size. You can specify the group means to compute the effect size.

[pic 43][pic 44][pic 45][pic 46][pic 47][pic 48]

• Or you can specify the between-group and the within-group variances to calculate the effect size

[pic 49][pic 50][pic 51]

• Sample size for the Chi-square test

[pic 52][pic 53][pic 54][pic 55][pic 56]

• Again, you can input basic information by pressing the “Determine” button to calculate the effect size

[pic 57][pic 58][pic 59][pic 60][pic 61]