Many South Carolina districts can't reduce class size because they have no space for more classrooms, Coleman said. And the effects continue to be felt. A national study of 20,000 students in fourth and eighth grades correlated students' performance on National Assessment of Educational Progress tests to class size. It found that students in small classes performed better even considering demographics and socioeconomic status. The Carnegie Foundation concluded there is no greater discouragement to in-depth instruction than overcrowded classrooms.
Some experts dismiss class size data.
Education scholar Herbert J. Walberg, a research professor of education and psychology at the University of Illinois at Chicago, says class size reduction is one of the most expensive yet unproven education policies. But small classes make perfect sense, most educators agree. But you cannot legislate smaller class size without providing the other things necessary to create good learning environments. School design School design, educators agree, is the key to creating good places for learning. Ninety percent of those surveyed by Heery said school design and condition are important for creating an effective learning environment.