A 2011 review by the Brookings Institution of the large body of studies on class sizes said the conclusions, while tentative, do suggest that having fewer students in class "can have significant long-term effects on student achievement."
A definitive study on the subject, the Student Teacher Achievement Ratio, conducted in Tennessee in the late 1980s, found that classes with 15 students achieved more than classes with 22 — with the smaller classes gaining the equivalent of three extra months of instruction.
It is worth nothing that a study by the McKinsey & Co. global management consulting firm found that students in some developed countries were not helped by smaller classes.
But studies or not, virtually any teacher in the United States will tell you that a smaller class size is their preference. Fewer students better enables them to provide one-on-one attention, especially to those children with the greatest educational needs — among them the poor, English language learners, and special education students.
Nowhere is the impact of smaller class sizes felt more than in urban schools, where overcrowding and violence can impact learning. Some classes in the Philadelphia public schools have as many as 33 students. That’s too many. Statewide, the average is 21. The national average is 20 in elementary schools and 19 in high schools, according to federal data.
Despite a projected $218 million budget shortfall, the Philadelphia School District plans to proceed with plans to reduce its kindergarten through third-grade classrooms to no more than 25 students in each class.
Smaller classes require more teachers and costs more money. But the move makes sense in Philadelphia, where nearly half of the students cannot meet reading and math benchmarks. They need the extra attention gained with smaller classes.
Sadly, if Gov. Corbett doesn’t increase funding for public education, smaller class sizes will increasingly become an expensive investment that many districts won’t be able to afford.
Fixing the public schools and improving student performance is more complicated, of course, than simply having smaller classes. There are other factors that yield good results, including putting the best teachers in the classrooms with a strong curriculum and safe schools.
But keeping classes small should be a priority. They are a vital part of the lesson plan for students to succeed.