Quality schooling is measured in many ways. No matter the measures used, though, small classes produce better results. Recognizing and building on students' successes helps them gain confidence as well as knowledge. Each student's own achievement level, learning rate, and overall ability can be considered. Larger classes prevent students from getting enough of the specific attention and practice that critical thinking and problem solving demand.
Teachers become more innovative.
They use new practices and ideas invented by others and themselves. Teachers use those new practices to bring about more student involvement. The students participate more. Teachers foster student responsibility. It's easy for students to get lost in a crowd.