Only those not in daily contact with the realities of class teaching can say that “squeezing a couple of extra pupils into most classes makes little or no difference to results” (“We are facing a crisis - so let’s think the unthinkable”, 30 March). It may indeed be the case that, in the narrow range of exam outcomes we currently deem it appropriate to measure, differences are undetectable. Yet every teacher knows that class size affects a range of areas highly important to both children and adults.

There is the one-to-one support that has to be spread more thinly, the diminished opportunities to contribute to whole-class discussions, the lack of space in a crowded classroom and the increased difficulty of maintaining good behaviour, not to mention the extra marking, the extra parents to see, the extra reports to write.

If we could measure these factors, I think research would show that packing children in does have negative effects. And if this is not the case, why not return to classes of 50?

Lana Boztas, Reigate, Surrey.