Reducing Class Sizes a Waste of Resources?

Large study says small class sizes don’t improve pupils’ resilience or grades.
Mar 13, 2024
Perhaps less is not more when it comes to class sizes.

Smaller class sizes in schools fail to increase the resilience of children from low-income families according to data on thousands of disadvantaged secondary school students in China and Japan.

Instead, the researchers say that resilience is improved by the quality of teachers, such as those with high discipline standards and who use their expertise to improve learning.

The study authors urge policymakers to invest more in high-quality teachers and not to waste resources on cutting down the number of children in each class.

“This study supports the view that the quality of teachers, rather than the quantity, is the primary guarantee of students’ resilience,” says lead author Professor Tao Jiang, of Taizhou University whose research team included experts from his and other China-based universities Northwest Normal, and Southwest.

“Quality teachers who effectively used teaching methods and managed classroom discipline increased the odds that individuals became resilient students.

“On the other hand, emphasizing the reduction of class sizes in schools may not benefit resilience. Smaller classes either had no relevance to resilience or were disadvantageous for resilience.

“Excessive emphasis on reducing class sizes is unnecessary, as it is detrimental to the emergence of students with high levels of resilience. Instead of allocating financial resources to reduce class sizes, it would be more effective to invest in providing high-quality science teachers."

Dr Drew Miller Deputy Director of the University of Newcastle's Teachers and Teaching Research Centre, though, has cautioned that there are unanswered questions about the data, and has some problems with drawing conclusions from it.

"When it comes to the crucial issue of class sizes, there is no indication of what proportion of their classes were made up of the group of disadvantaged, high “resilience” students that the study concentrates on.

"Was there a high proportion of disadvantaged students in one class - normally associated with lower results - or a low proportion of disadvantaged students in a class - normally associated with higher results?

"Disadvantaged students in larger classes may have been in urban areas of mixed socio-educational status, and students in smaller classes may have been rural or remote students in smaller schools with higher levels of overall disadvantage. This is very important to any interpretation of the result,” Dr Miller said.

Additionally, the pattern of larger classes being associated with higher “resilience” was observed in Japan, but not in the Macao data. 

"Using PISA data for purposes such as this study is very enticing. There is a large amount of data, with many variables to slice and combine and analyse. However, the limitations of cross-sectional data to draw causal inferences and provide information about the ways teachers should teach should be noted here…strongly.

"Also… what percentage of students do 1502 in Japan, and 989 in Macao, actually make up in those highly populous regions? Drawing too strong an inference from relatively small samples of this nature is dangerous."

The original article was published in International Journal of Science Education

Image by Tima Miroshnichenko