In this paper, three-level hierarchical regression models (the first level represents the students; the second level, the classrooms; and the third level, the schools) are produced to explain levels of proficiency achieved in the Portuguese language assessment of the PROEB/SIMAVE-2002 - the Minas Gerais State Programme for the Assessment of Elementary Education, by students in the 4th year of elementary school. Results show that there is large variability explained by classroom differences, reasonable variability explained by school differences, and enormous variability explained by student differences. When the variables studied are introduced in the models, a substantial portion of the total variability is explained.
large scale educational assessment; hierarchical models of regression; three-level hierarchical models; partition of total variability