Catalogue de données central

The sample was drawn using a proportional stratified random sampling strategy. The country was divided into 16 strata based on geographical location, school location and school type. In the first stage, 25 districts out of 75 were randomly selected. In the second stage, schools were randomly sampled in the selected districts, the number of sampled schools being proportional to the number of schools in each stratum. Students in all grade 8 classrooms within selected schools were assessed.