Class Size Reduction Ineffectiveness
RCTJournal Article
Educational policy frequently assumes that reducing class sizes or creating more homogeneous student groups will automatically increase academic achievement without changing underlying teaching methods.
Picture this
Reducing the number of audience members in a lecture hall does not help the remaining listeners understand a presentation if the speaker continues delivering the material in a language that the audience cannot comprehend.
What the evidence says
The indirect treatment effect on non-remedial students remaining in smaller, more homogeneous classrooms was 0.133 standard deviations (statistically insignificant, with a 95% confidence interval ranging from -0.076 to 0.189).
- Who was studied
- N = 21,936 Grade 3 and Grade 4 students across municipal primary schools in Mumbai and Vadodara, India.
- How
- Instrumental Variables (IV) regression evaluating non-remedial peers who remained in regular classrooms with reduced class sizes while low-scoring peers attended remedial instruction.
What to do
Avoid expanding municipal education budgets solely to hire additional formal teachers for class size reduction without accompanying pedagogical reforms.
From the source
"In contrast, there is no discernible impact on their classroom peers, who were 'treated' with smaller class sizes and a more homogenous classroom, consistent with the previous literature suggesting that inputs alone are ineffective."
Remedying Education: Evidence from Two Randomized Experiments in India