Comment by zozbot234
20 days ago
How Does Class Size Vary Around the World? (OECD, 2012) shows that there are countries such as Japan and South Korea with some of the largest average class sizes, and excellent educational achievement. Clearly it's far from the only or even the most important factor. The United Kingdom is one country that skews the other way, though there are countries like Estonia with similarly small classes that seem to do a lot better.
I know nothing about those countries ratios.
But on the topic, I suspect the best time to have high teacher ratios is in the earliest years. Help children learn to manage themselves, focus, follow through, etc. Then work up to large class sizes in the upper years.