I attended private parochial elementary school and class size hovered from 30-35. Teachers ruled with an iron fist back then (in the olden days...long, long ago), but I really feel like class size was a non-issue.

That being said, I prefer that the non-iron-fist-ruling teachers in our local public schools have smaller class sizes. I especially prefer this, because we have usually been in need of differentiation. Class sizes tend to increase for the older children, but 20 for younger grades (sometimes less) is probably average.

Still, I know that one of the years has a larger number of children overall, and parents were very upset, because the class sizes were slightly larger this year than they typically are for most rooms.