Microsoft in Education Global Forum, Dubai, 2...
How effective is it?
Intuitively, it seems obvious that reducing the number of pupils in a class will improve the quality of teaching and learning, for example by increasing the amount of high quality feedback or one-to-one attention learners receive. However, overall the evidence does not show particularly large or clear effects, until class size is reduced to under 20 or even below 15.
The key explanation for this appears to be whether a reduction is large enough to permit the teacher to change their teaching approach when working with a smaller class and whether, as a result, the pupils change their learning behaviours. If no change occurs then, perhaps unsurprisingly, learning is unlikely to improve. When a change in teaching approach does accompany a class size reduction (which appears hard to achieve until classes are smaller than about 20) then benefits on attainment can have been identified, in addition to improvements on behaviour and attitudes. In some studies these benefits persist for a number of years (from early primary school through to at least the end of Key Stage 2). It appears to be very hard to achieve improvements from class size reductions above 20, e.g. from 30 to 25.
There is some evidence that reducing class sizes are more likely to be effective when supported with professional development to learn and develop teaching skills and approaches. Some evidence suggests slightly larger effects are documented for the lower achievers and those from the lower socio-economic status for very young pupils. Additionally teachers may potentially further develop their teaching skills and approaches in a smaller class.
Interesting class sizes in Singapore and Chine, two high performing countries, are around 40 children.
What are your thoughts regarding class sizes