Sample Size Growth with an Increasing Number of Comparisons

Figure 1

Sample size versus log𝑀 (base 10) to detect effect sizes Δ=0.5,1 or 2 with 1−𝛽=90% power at the familywise significance level 𝛼=5%, when Bonferroni adjustment is used. The open circles represent the sample sizes calculated based on exact normal quantiles (2.2).