Summary of effect sizes for different approaches to power calculations
| Method | Effect size (Δ/σ) |
|---|---|
| Two groups (Fleiss) | 0.43 |
| Two groups, different ρ | 0.33–0.43 |
| MANCOVA (2 groups, ρ=0.5, 0.6, 0.7) | 0.55, 0.49, 0.43 |
End point differences and MANCOVA effect sizes under different assumptions about the correlation between baseline and end point mean values of the outcomes.