Table 2.
Power estimates for two-way interaction effect between predictors of various interrelations
| Two-tailed p < .05 | ||||||||||||
| N | r = .05, d = .10 | r = .10, d = .20 | r = .20, d = .41 | |||||||||
| r ab | 0 | .10 | .30 | .50 | 0 | .10 | .30 | .50 | 0 | .10 | .30 | .50 |
| 50 | 6% | 4% | 5% | 5% | 9% | 9% | 8% | 7% | 20% | 25% | 24% | 17% |
| 100 | 5% | 6% | 6% | 6% | 16% | 14% | 14% | 14% | 45% | 47% | 48% | 43% |
| 150 | 8% | 9% | 7% | 8% | 21% | 20% | 22% | 17% | 60% | 62% | 63% | 54% |
| 200 | 10% | 12% | 10% | 9% | 30% | 26% | 24% | 24% | 79% | 78% | 76% | 71% |
| 250 | 11% | 10% | 10% | 11% | 33% | 31% | 31% | 26% | 87% | 85% | 84% | 82% |
| 300 | 12% | 14% | 14% | 12% | 40% | 37% | 35% | 31% | 92% | 93% | 91% | 86% |
| 350 | 14% | 13% | 12% | 13% | 41% | 40% | 38% | 35% | 94% | 95% | 94% | 92% |
| 400 | 16% | 14% | 16% | 14% | 49% | 50% | 46% | 42% | 97% | 98% | 96% | 93% |
| 450 | 17% | 20% | 17% | 15% | 49% | 52% | 55% | 43% | 98% | 98% | 98% | 96% |
| 500 | 19% | 19% | 21% | 16% | 56% | 62% | 54% | 52% | 99% | 100% | 99% | 98% |
| 750 | 24% | 28% | 24% | 24% | 73% | 75% | 69% | 65% | 100% | 100% | 100% | 100% |
| 1,000 | 30% | 32% | 31% | 28% | 86% | 84% | 86% | 78% | 100% | 100% | 100% | 100% |
| 2,500 | 69% | 66% | 65% | 61% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| 5,000 | 92% | 92% | 92% | 87% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| 7,500 | 98% | 99% | 98% | 95% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| 10,000 | 100% | 100% | 100% | 99% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| One-tailed p < .05 | ||||||||||||
| N | r = .05, d = .10 | r = .10, d = .20 | r = .20, d = .41 | |||||||||
| r ab | 0 | .10 | .30 | .50 | 0 | .10 | .30 | .50 | 0 | .10 | .30 | .50 |
| 50 | 10% | 9% | 9% | 9% | 16% | 17% | 14% | 13% | 31% | 37% | 35% | 31% |
| 100 | 13% | 12% | 11% | 11% | 25% | 24% | 22% | 21% | 58% | 59% | 61% | 55% |
| 150 | 15% | 13% | 16% | 13% | 31% | 31% | 30% | 25% | 71% | 74% | 73% | 69% |
| 200 | 18% | 16% | 16% | 15% | 39% | 39% | 35% | 32% | 86% | 87% | 86% | 81% |
| 250 | 20% | 18% | 17% | 17% | 46% | 45% | 41% | 37% | 92% | 91% | 92% | 89% |
| 300 | 19% | 22% | 20% | 17% | 49% | 49% | 47% | 41% | 96% | 96% | 95% | 92% |
| 350 | 24% | 20% | 21% | 19% | 53% | 57% | 54% | 47% | 97% | 98% | 96% | 96% |
| 400 | 25% | 26% | 24% | 20% | 61% | 62% | 56% | 53% | 98% | 99% | 99% | 97% |
| 450 | 25% | 28% | 26% | 23% | 60% | 65% | 66% | 53% | 99% | 99% | 99% | 98% |
| 500 | 28% | 26% | 28% | 23% | 67% | 72% | 64% | 62% | 100% | 100% | 100% | 99% |
| 750 | 35% | 38% | 34% | 32% | 84% | 83% | 80% | 76% | 100% | 100% | 100% | 100% |
| 1,000 | 40% | 46% | 42% | 40% | 92% | 91% | 91% | 86% | 100% | 100% | 100% | 100% |
| 2,500 | 78% | 77% | 74% | 71% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| 5,000 | 96% | 96% | 95% | 92% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| 7,500 | 99% | 100% | 99% | 98% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| 10,000 | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
Note: r and d values represent the effect size of the interaction term and these can be interpreted as partial rs; rab represents the correlation between the two predictor variables; for the continuous predictors and the dependent variable, we assumed α = .85; in this table, we present power estimates for analyses with two continuous predictors (both α = .85), given that these results were very highly overlapping with analyses with one continuous predictor (α = .85) and one dichotomous predictor (α = 1).