| Grade | Attended Grade | 11th (early enrolees), 10th (regulars), 9th, 8th and 7th (late enrolees and students who have failed the year) |
| Month of birth |
| 1st JANUARY-31st DECEMBER |
| Gender | Students’ gender | 1 if female |
| Failure | Grade failure | 1 if student has failed the year |
| Nationality | Immigration status | 1 if immigrant |
| Math | Index of performance in Mathematics | From 1—very low to 6—very high |
| Reading | Index of performance in Reading | From 1—very low to 6—very high |
| Science | Index of performance in Science | From 1—very low to 6—very high |
| Mother Education | Mother’s education level | ISCED levels |
| Father Education | Father’s education level | ISCED levels |
| Mother Occupation | Mother’s occupational status | Discreate variable: 0—unemployed: 1—elementary occupations; 2—plant and machine operators; 3—clerks; 4—professionals. |
| Father Occupation | Father’s occupational status | Discreate variable: 0—unemployed: 1—elementary occupations; 2—plant and machine operators; 3—clerks; 4—professionals. |
| ESCS | Index of economic, social and cultural status | Composite score built by the following indicators: parental education, highest parental occupation and home possessions. |
| Region | Students’ school geographical localization | 1—North West; 2—North East; 3—Centre; 4—South; 5—Islands. |
| Hours of Sport | Hours of sport performed on average during a week in the presence of a coach | Discrete variable ranging from 0 to 20. |