| Grades | N | Mean | SD | F | sig. |
1-Environmental awareness | 9th | 154 | 26.75 | 5.82 | 1.990 | .115 |
10th | 46 | 26.78 | 5.49 | |||
11th | 53 | 25.58 | 5.48 | |||
12th | 77 | 28.19 | 7.43 | |||
2-Attitude toward recovery | 9th | 154 | 11.59 | 2.70 | 1.999 | .114 |
10th | 46 | 12.63 | 3.89 | |||
11th | 53 | 12.28 | 2.76 | |||
12th | 77 | 12.34 | 3.44 | |||
3-Attitude toward recycling | 9th | 154 | 11.06 | 3.25 | 3.136 | .026 |
10th | 46 | 12.17 | 3.30 | |||
11th | 53 | 11.01 | 2.59 | |||
12th | 77 | 12.13 | 3.18 | |||
4-Environmental consciousness and behavior | 9th | 154 | 15.10 | 4.33 | 3.032 | .029 |
10th | 46 | 16.74 | 3.73 | |||
11th | 53 | 15.19 | 3.50 | |||
12th | 77 | 16.34 | 3.92 |