Is Less Really More? On the Relationship between Class Size and Educational Achievement in Israel
Author: Reut Shafrir, Yossi Shavit and Carmel Blank Policy Research

This study shows that, when controlling statistically for parental education levels and prior attainments, the relationship between class size and achievement is not significant.

The impact of class size on pupil achievement has been a matter of concern to education professionals for many years. Parents and teachers argue that large classes are detrimental to learning, but education researchers have yet to reach an unequivocal conclusion on the topic. The main challenge in assessing the relationship between class size and pupil performance is controlling for class placement, which is not random and could therefore potentially distort findings.

The present study looks at the topic in the Israeli context, through a hierarchical analysis of the scores of pupils who took the Israeli Meitzav exams in 2006 and 2009 using three models: a model containing only class size, a model controlling for background variables such as prior achievements and parental educational levels, and a model that also includes interaction variables aimed at determining whether class size has a different effect on pupils from populations with weaker educational abilities and lower socioeconomic status than pupils with high educational abilities from higher ­­­socioeconomic status.

The findings indicate that, when controlling statistically for parental education levels and prior attainments, the relationship between class size and achievement is not significant. Thus, small classes do not seem to enhance the achievement of their students. The hypothesis that the impact of class size on achievement varies between social strata and between stronger and weaker pupils was also refuted: no difference in the relationship between class size and achievement was found among the groups.

It is important to note that the study’s findings indicate that class size in and of itself does not ensure improved pupil achievement. Small classes could facilitate the use of teaching methods that may help students achieve – for example, individualized or small-group instruction. However, it is unclear whether teachers working in small classes do, in fact, take advantage of the possibilities that such classes present, including the teaching methods suited to them. They might be using forms of pedagogy similar to those commonly employed in large classes, and effectively neutralizing the small-class advantage.

This paper appears as a chapter in the Center’s annual publication, State of the Nation Report 2016edited by Prof. Avi Weiss.