For many it is blindingly obvious- smaller classes result in greater
achievement. How could it not? Smaller classes must mean better
behaviour and more one-to one support and feedback from the teacher.
Smaller classes must be less draining for the teacher, and therefore
result in lessons with more pace and energy...
Unfortunately that’s not what the evidence says. Hattie synthesizes the
results from 96 studies involving more than half a million students, and
in the end he provides an effect size of 0.21.
Why such a small effect?
Hattie (2009) considers in some depth the reasons why such a seemingly obvious intervention should lead to
such a marginal effect. His conclusion is that teaching approaches don’t seem to change in response to
reductions in class size, it’s simply ‘business as usual’ at the chalkface.
Reductions in class size need to be met with a change in practice to embrace additional:
Active involvement in learning activities