Ao contrário de “estudos”, artigos e bitaites avulsos (neste caso, do Reitor de serviço ao domingo, conforme comentário no post abaixo), não é verdade que a dimensão das turmas seja um factor irrelevante para a qualidade das aprendizagens dos alunos ou que as “evidências sejam contraditórias” ou qualquer variante desta falácia muitas vezes repetida por muita gente. É mentira. Por muito que venham com exemplos asiáticos de 1265 alunos numa sala de aula, todos geniais em Matemática. É mentira, repito.
O problema é que a redução de 1 ou 2 alunos por turma, em especial com a escolaridade já adiantada, tem efeitos efeitos que não são estatisticamente extraordinários em termos de desempenho, em especial se soubermos escolher o que comparar, como acontece com muitos estudiosos comprometidos com a eficácia financeira.
A verdade é que o número dos alunos por turma deve obedecer a dois princípios essenciais: o das turmas serem pequenas nos primeiros anos de aprendizagem e o de, mais tarde, o número de alunos se manter baixo por turma.
Claro que podemos sempre sacar de imensas citações, mas eu vou ficar por poucas, umas mais distantes e outra mais recente. De estudos que, em regra, certos investigadores nunca lêem ou, se lêem, fazem por nunca citar. Mesmo se forem do Brookings Institute…
The most influential and credible study of CSR is the Student Teacher Achievement Ratio, or STAR, study which was conducted in Tennessee during the late 1980s. In this study, students and teachers were randomly assigned to a small class, with an average of 15 students, or a regular class, with an average of 22 students. This large reduction in class size (7 students, or 32 percent) was found to increase student achievement by an amount equivalent to about 3 additional months of schooling four years later.
Small classes may vary in other ways, in addition to student-teacher ratio, depending upon school leadership, facilities, and teaching staff, as well as official policy. The typical model is one teacher in one classroom teaching an assigned number of students, but other models have been implemented.
Project STAR defined two categories of reduced size classes:
- Classes of 13 to 17 students taught by one teacher; and
- Classes of 22-26 taught by a teacher and a teacher’s aide.
Project STAR defined large classes as 22-26 students taught by one teacher.
Wisconsin’s SAGE had four categories of classrooms, all intended to achieve the mandated 15:1 ratio (Molnar, 1999):
Regular classroom (15 or fewer students with one teacher);
Team-teachers classroom (30 or fewer students in a classroom with two teachers);
Shared-space classroom (a regular classroom divided by a temporary wall with one teacher and 15 students on either side of the divider); and
Floating teacher classroom (30 students with one teacher plus an additional teacher during reading, language arts, and mathematics).
The academic literature strongly supports the common-sense notion that class size is an important determinant of student outcomes. Class-size reduction has been shown to improve a variety of measures, ranging from contemporaneous test scores to later-life outcomes such as college completion.
Based on the research literature, I offer the following policy recommendations:
Class size is an important determinant of student outcomes and one that can be directly influenced by policy. All else being equal, increasing class sizes will harm student outcomes.
The evidence suggests that increasing class size will harm not only children’s test scores in the short run but also their long-term human capital formation. Money saved today by increasing class sizes will be offset by more substantial social and educational costs in the future.
The payoff from class-size reduction is larger for low-income and minority children, while any increases in class size will likely be most harmful to these populations.
Policymakers should carefully weigh the efficacy of class-size-reduction policy against other potential uses of funds. While lower class size has a demonstrable cost, it may prove the more cost-effective policy overall.