Table 1 Bias (standard deviation units) in respect of ANCOVA versus ANOVA and ANCOVA versus CSA
Difference | Z′ T –Z′ C | Treatment effect | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Â | 0.2 | 0.5 | 0.8 | ||||||||||||||||
| Â | ZYcorrelation | ZYcorrelation | ZYcorrelation | ||||||||||||||||
| Â | Â | 0 | 0.1 | 0.3 | 0.5 | 0.7 | 0.9 | 0 | 0.1 | 0.3 | 0.5 | 0.7 | 0.9 | 0 | 0.1 | 0.3 | 0.5 | 0.7 | 0.9 |
ANCOVA – ANOVA | −1.96 | 0.00 | 0.01 | 0.04 | 0.07 | 0.10 | 0.13 | 0.00 | 0.03 | 0.10 | 0.17 | 0.24 | 0.31 | 0.00 | 0.05 | 0.16 | 0.27 | 0.38 | 0.49 |
−1.64 | 0.00 | 0.01 | 0.04 | 0.06 | 0.08 | 0.11 | 0.00 | 0.03 | 0.09 | 0.14 | 0.20 | 0.26 | 0.00 | 0.04 | 0.14 | 0.23 | 0.31 | 0.41 | |
−1.28 | 0.00 | 0.01 | 0.03 | 0.05 | 0.06 | 0.08 | 0.00 | 0.02 | 0.07 | 0.11 | 0.16 | 0.20 | 0.00 | 0.03 | 0.10 | 0.17 | 0.25 | 0.32 | |
0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.01 | 0.01 | 0.00 | 0.00 | |
1.28 | 0.00 | −0.01 | −0.03 | −0.04 | −0.06 | −0.08 | 0.00 | −0.03 | −0.07 | −0.11 | −0.16 | −0.21 | 0.00 | −0.04 | −0.11 | −0.18 | −0.25 | −0.32 | |
1.64 | 0.00 | −0.01 | −0.03 | −0.06 | −0.08 | −0.11 | 0.00 | −0.03 | −0.09 | −0.15 | −0.21 | −0.26 | 0.00 | −0.05 | −0.14 | −0.23 | −0.32 | −0.41 | |
1.96 | 0.00 | −0.01 | −0.04 | −0.07 | −0.10 | −0.13 | 0.00 | −0.04 | −0.11 | −0.18 | −0.24 | −0.31 | 0.00 | −0.06 | −0.17 | −0.28 | −0.38 | −0.49 | |
ANCOVA – CSA | −1.96 | −0.14 | −0.13 | −0.10 | −0.07 | −0.04 | −0.01 | −0.35 | −0.31 | −0.24 | −0.17 | −0.10 | −0.03 | −0.55 | −0.49 | −0.38 | −0.27 | −0.16 | −0.05 |
−1.64 | −0.12 | −0.11 | −0.08 | −0.06 | −0.04 | −0.01 | −0.29 | −0.26 | −0.20 | −0.15 | −0.09 | −0.03 | −0.46 | −0.41 | −0.31 | −0.22 | −0.14 | −0.05 | |
−1.28 | −0.09 | −0.08 | −0.06 | −0.05 | −0.03 | −0.01 | −0.23 | −0.20 | −0.16 | −0.12 | −0.07 | −0.03 | −0.36 | −0.32 | −0.25 | −0.17 | −0.10 | −0.03 | |
0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |
1.28 | 0.09 | 0.08 | 0.06 | 0.05 | 0.03 | 0.01 | 0.23 | 0.20 | 0.16 | 0.11 | 0.07 | 0.02 | 0.35 | 0.32 | 0.25 | 0.18 | 0.11 | 0.04 | |
1.64 | 0.12 | 0.10 | 0.08 | 0.06 | 0.04 | 0.01 | 0.29 | 0.26 | 0.20 | 0.15 | 0.09 | 0.03 | 0.45 | 0.41 | 0.32 | 0.23 | 0.14 | 0.05 | |
| Â | 1.96 | 0.14 | 0.13 | 0.10 | 0.07 | 0.04 | 0.02 | 0.35 | 0.31 | 0.24 | 0.17 | 0.10 | 0.04 | 0.54 | 0.49 | 0.38 | 0.27 | 0.16 | 0.05 |