From USA Today:

New findings from four nations, including the USA, tell a curious story. Small classes work for children, but that’s less because of how teachers teach than because of what students feel they can do: Get more face time with their teacher, for instance, or work in small groups with classmates.

Researchers found that class size had little effect on the way that teachers taught their students. With teaching behavior remaining largely the same in both large and small classes, any benefits that smaller class sizes had were likely the result of students’ perception that the smaller classes were better for them. They feel that they can do more in a smaller class.

Put simply, it’s all in their head.

This raises an interesting question. If teachers reinforce the perception that they are more attuned to individual student needs, regardless of the size of the class, do the students learn more?