| Source of changes | Sum of squares | Degrees of freedom | Mean square | F | Significance level | Eta coefficient |
| Pretest | 10.9 | 1 | 10.9 | 70.9 | 0.000 | 0.73 |
| Main effect | 0.93 | 1 | 0.93 | 6.1 | 0.02 | 0.19 |
| Remaining error | 3.9 | 20 | 0.19 | - | - | - |