Reducing class sizes has long been championed as a way to improve outcomes for students.
Supporters – including many parents and teachers – argue that smaller classes allow students to get more individual attention and result in better grades, better test scores and fewer disciplinary issues. But critics of class-size reduction efforts argue that such reforms simply take money away from other priorities without making a meaningful difference in children’s learning.
“No one’s going to argue against the substantive argument for reducing class sizes, right?” says Douglas Ready, a professor of education and public policy at Columbia University in New York. “It sounds great. Teachers want it. Parents want it. Everybody wants it. The issue is paying for it and finding teachers to do it.”
Benefits and Challenges of Smaller Classes
Unlike other areas of education research, Ready says, there have been large-scale, randomized control trials – generally considered the gold standard in research design – examining the effects of class-size reduction. These studies found that smaller classes correlate with better test scores.
In 1985, Tennessee launched an experiment, the Student/Teacher Achievement Ratio (STAR) project, in which it assigned 7,000 kindergarten students in 79 schools to classes of varying sizes.
After four years, the students who had been placed in small classes were between two and five months ahead of their peers in larger classes, according to a report on the study in the academic journal Teachers College Record. Even once the experiment ended and students returned to full-size classrooms, students who had been in the smaller groups continued to benefit. By eighth grade, they were almost a full school year ahead of their peers.
Then in 1996, Wisconsin conducted a similar experiment targeting schools serving low-income students and comparing adolescents in classrooms of 12 to 15 with students in classrooms of 21 to 25 students. Here again, students in smaller classes achieved higher test scores, according to a federal examination of the study.
“The research is crystal clear that smaller classes lead to better student outcomes in every single way that can be measured,” says Leonie Haimson, executive director of Class Size Matters, a nonprofit that advocates for smaller class sizes.
But results from more recent studies using different methods have been mixed.
For one, reducing class sizes means hiring more teachers, which has long been a challenge for districts, Ready says.
A study of class-size reduction in New York City public schools from 2009 to 2013 found that many of the gains in test scores were offset by declines due to the “new teacher effect.” The report concludes that reducing class sizes can “substantially improve student achievement,” but only if schools can do so without affecting teacher quality.
In 1996, California launched an initiative to reduce class sizes by providing $650 to districts for every student in a kindergarten through third grade classroom with 20 or fewer students. Districts quickly hired about 30,000 new teachers, and the program cost the state billions of dollars.
Many of those educators were inexperienced and uncertified, according to a report from the Public Policy Institute of California. And the problem was particularly acute for Black students at schools with predominantly low-income students, where nearly 25% of students had a teacher with two years of experience or less, and 30% had a teacher who was not fully credentialed. Among white students at schools with fewer poor students, only 12% of students had a teacher with two years of experience or less, and only 5% had a teacher who was not fully credentialed.
Still, an analysis of studies on the class-size reduction program show that it “had a positive and significant influence on student achievement,” according to a Princeton University researcher. “Black students seem to have benefited” from class-size reduction “more than any other racial or ethnic group.”
Alternatives to Reducing Class Size
Some education experts argue that the billions of dollars needed to fund widespread class-size reduction efforts would be better spent on increasing teachers’ salaries, “thus increasing the size (and arguably the quality) of the teacher labor pool,” Ready wrote in a report.
Although researchers say that claims of a nationwide teacher shortage are exaggerated, many school districts have been struggling to fill roles during the pandemic. In January 2022, 44% of public schools reported having at least one vacancy and 61% identified the COVID-19 pandemic as a cause of increased teacher and staff vacancies, according to federal data.
The number of people entering the teaching profession has also decreased over the decades. In the 1970s, there were more than 200,000 undergraduate education degrees awarded annually; in 2018, there were less than 90,000, according to the American Association of Colleges for Teacher Education.
“We are in a moment of extreme teacher shortage, and it’s likely to get worse,” says Bryan Hassel, co-president of Public Impact, an education advocacy group. “The idea that we would say now in that environment, ‘You need to find and keep another 25, 30, 40% more teachers,’ is a recipe for disaster because who’s going to fill those slots?”
Instead, states and school districts should try to increase their capacity for small-group tutoring by hiring paraprofessionals, such as teaching assistants, Hassel argues.
“There is strong evidence that having small groups learn from a teacher or a paraprofessional in a tutoring setting is very effective,” Hassel says. “Schools really should be trying to increase the amount of that that goes on, but that can happen in a larger class. You can have 25 kids in a room. Some are working intensively in a tutoring environment with the teacher; the others are doing projects, doing other work.”
What Parents Can Do
Haimson recommends that parents share studies on the benefits of reducing class size with principals, school board members and elected officials.
“Whether you’re talking about academic achievement or social, emotional recovery from the pandemic, the best way to ensure that happens for all kids is to be able to offer them small classes,” she says. “We hope that parents will act as their children’s advocates and push for that at the local level.”
Meanwhile, Ready suggests parents focus on teacher quality.
“If a district can afford to have smaller class sizes and maintain teacher quality, great,” he says. “But in most parts of the U.S., there are trade-offs.”
Parents who are concerned about their children being in a large class should ask the teacher or others at the school “what plans they have to ensure that kids are getting individual attention even though the class is large, such as small-group work within the large class” or having more paraprofessionals, Hassel says.
“The value of small classes likely comes from the extra attention students get,” he notes, “and so there are other ways to get students that attention if you’re stuck with a large class.”