| Source of changes | Sum of squares | Degrees of freedom | Mean square | F | Significance level | Eta coefficient |
| Pretest | 3582.1 | 1 | 3582.1 | 153.7 | 0.000 | 0.86 |
| Main effect | 121.5 | 1 | 121.5 | 5.2 | 0.03 | 0.17 |
| Remaining error | 605.8 | 20 | 30.3 | - | - | - |