Table 2 Sample sizes required for 90% power and 1% two-sided alpha: interaction
From: Design, analysis and presentation of factorial randomised controlled trials
| Magnitude of effects (in units of standard deviations) | ||
|---|---|---|
| Main effect | Interaction | Total sample size to detect interaction |
| 0.3 | 0.6 | 664 |
| 0.3 | 0.3 | 2656 |
| 0.3 | 0.15 | 10624 |