Class sizes have biggest impact in early years, education studies suggest

Want to weigh in on this topic? Try out our new Good Talk video commenting feature.

The loss of a 20-pupil limit in Manitoba's kindergarten to Grade 3 classrooms appears to go against study findings that suggest those early years are when class sizes matter most to educational outcomes.

Education and Training Minister Ian Wishart announced Tuesday that the province is dumping legislation that required the cap on early-years class sizes because, he said, there is not adequate data to demonstrate its effects on student performance — positive or otherwise.

The Manitoba Teachers' Society said it was alarmed by the decision to scrap the previous NDP government's legislation because the cap, introduced in 2011, was not given enough time to get off the ground.

NDP education critic Wab Kinew echoed the concerns Tuesday, and said parents want smaller classes, believing they lead to better outcomes.

Education experts who have studied class sizes say the early years appear to be the time when class sizes matter the most.

"Simply put … class size is an attractive policy target for politicians because it is easily understood by the electorate," Yvan Guillemette, a policy analyst at the C.D. Howe Institute, wrote in a 2005 study. 

"No solid evidence exists to show that smaller classes improve student achievement in the later primary and secondary grades in Canada," his study said. 

Guillemette said teachers have put pressure on governments to reduce class sizes but in his opinion, smaller is not better.

Russ Whitehurst, senior fellow in economic studies at the Brookings Institution think tank in Washington, D.C., disagrees — with a caveat.

"It looks like you get bigger effects in the earliest grades than if you wait until the later grades," he said.

Invest in good teachers, expert says

Much of what education experts know about small class sizes comes from a study into the issue conducted in Tennessee that began in 1985 and ended four years later.

Researchers in that state watched the effect on children of classes with around 15 students compared with classes of between 20 and 25 children. More than 11,500 students were part of the study.

"Compelling evidence that smaller classes help, at least in early grades … leaves open the possibility that additional or different educational devices could lead to still further gains," the Tennessee study said.

It added that techniques like "within-class grouping," in which teachers work with smaller in-class groups for short periods, could produce better results.

"The point is that small classes can be used jointly with other teaching techniques, which may add further gains," the study said.

Whitehurst said the Tennessee study also showed that small classes have the largest effect on young students from minority backgrounds.

But, he said, if school divisions want to have an even greater impact, they should invest in good teachers rather than smaller class sizes.

"Anything you can do to get higher quality teachers in the classroom and to remain in the classroom … produces real effects on students," Whitehurst said.

"One year in the classroom of a really effective teacher produces changes in labour market returns and earnings when kids grow up and enter the workforce."

University of Melbourne education expert John Hattie says focusing on class size is a distraction because even as class sizes shrink, teachers may not change their approach with students.

Instead, Hattie recommends focusing on developing good teachers and making learning more personal for students.

A 2014 study by Northwestern University's Diane Whitmore Schanzenbach that looked at 30 years of research, though, found that class size does matter for younger children.

"All else being equal, increasing class sizes will harm student outcomes," Whitmore Schanzenbach wrote.

"Money saved today by increasing class sizes will result in more substantial social and educational costs in the future."

CBC News is partnering with GoodTalk, a new engagement tool that lets Canadians watch and record video comments on top stories and even get featured on the CBC. Follow the links to try it out.