A growing body of research supports the importance of small classes in K-12 education. A 2011 study by the Brookings Institution found that students in small classes (16-18 students or fewer) outperformed those in larger classes (22 students or more) by a rate equivalent to three months of additional schooling every four years. This means that students who begin kindergarten in small classes are nearly one year ahead of their peers in larger classes by eighth grade.