Study design
Power analysis
10 min
Learning goals
- •You can explain what statistical power means.
- •You understand the trade-off between Type I and Type II errors.
- •You can determine the sample size required for a desired power.
0.50
30
0.05
Sampling distribution of the difference under H₀ and H₁
Power (1 − β):47.8 %
n (per group):30(Total N: 60)
d (Cohen):0.50
α:0.050
α (Type I error)
β (Type II error)
Power (1 − β)
Power curve (power vs. n (per group))