A recent study challenges the common belief that smaller class sizes improve student outcomes. The research, which analyzed data from over 2,700 students in China and Japan, found that reducing classroom sizes does not lead to better grades or higher resilience among low-income secondary-level students. Surprisingly, smaller classes might even hinder students’ chances of achieving better results in some cases.
Instead, the researchers discovered that what improved student outcomes was the quality of the teachers. Teachers with high discipline standards, expertise, and effective learning strategies were found to be beneficial.
The study strongly suggests that policymakers should reconsider decreasing class sizes. The authors argue that resources are better spent on nurturing higher-quality teachers rather than spreading mediocre educators thin across small classrooms.
Lead author Professor Tao Jiang of Taizhou University stated, “This study supports the view that the quality of teachers, rather than the quantity, is the primary guarantee of students’ resilience.”
“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.”
Prioritizing good teachers over classroom size is recommended by the study.
The study examined various factors affecting the resilience of 1,594 disadvantaged science students in Japan and 1,114 in the Macau region of China. In this context, academic resilience refers to the capacity of students to confront adversity and thrive academically by earning good grades despite these obstacles. Learning scholars claim that academic resilience is not fixed but is rather a trainable quality that improves with practice and repeated success, with small wins stacking to improve the student’s overall resilience in the classroom.
All the participants were part of the Programme of International Student Assessment (PISA), an international questionnaire-based survey. PISA measures a pupil’s ability to use their reading, mathematics, and science knowledge and offers a benchmark to evaluate learning quality across different countries.
The findings revealed that about a third of the students demonstrated high resilience, a quarter showed low resilience, and the remainder fell into the medium category. Those with high resilience had a more positive attitude towards school, science, and their future career prospects. They spent more time studying science but also reported feeling anxious about exams.
Contrary to expectations, smaller class sizes did not consistently contribute to better resilience. In some cases, they even had a negative effect. For instance, in Japan, reducing class size was detrimental, whereas a slight increase in class size significantly improved disadvantaged students’ chances of achieving better grades. The researchers didn’t suggest why this was the case — it is just an observation for the time being.
Beyond classroom numbers
Interestingly, the study discovered that in Japan, inquiry-based learning was the most effective way to improve resilience, while in Macau, direct instruction from teachers had a bigger impact. Inquiry-based learning encourages students to explore and find answers through questions and experiments, while direct instruction involves a structured approach where teachers explicitly teach specific skills or knowledge.
The effect of class size was different, with smaller classes not influencing resilience in Macau and having a negative impact in Japan. However, a slight increase in class size in Japan was linked to a 1.2-fold increase in the chances of disadvantaged students achieving higher grades.
In addition, the study revealed that classroom and school misbehavior have a negative effect on student resilience. Classrooms where teachers enforced rules, maintained discipline, and adapted lessons to meet student's needs tended to do the best.
The study communicates a clear message: quality teaching is more important than class size in improving the resilience and academic performance of disadvantaged students. However, this is not the final word on the subject.
Still more to learn
The study focused on students in Japan and China and mainly on science classes with pupils from low-income backgrounds. Previous studies have found that smaller classes lead to greater classroom engagement and higher attendance. In some research, the impact of small classes is more modest.
“Most studies find at least some evidence of positive effects of smaller classes, but the size of these benefits is inconsistent,” wrote Urban Institute researcher Matt Chingos.
The new finding changes the discussion from quantitative adjustments in class size to qualitative improvements in teaching. It calls for targeted investments in teacher development and training as the most effective way to support student success, especially among those from low-income backgrounds. However, a mix of both — training better teachers and reducing class sizes — should not be overlooked, although this is definitely difficult to implement due to the limited resources allocated to primary education worldwide.
The findings appeared in the International Journal of Science Education.
