The push to create more charters has been questioned in light of research showing no advantage – or even a negative effect – for students attending charter schools. Such research includes a much-publicized study a year ago from the Center for Research on Education Outcomes (CREDO). Several other, narrower studies – including one on New York City charters and a study that came out last week on charter schools operated by the Knowledge Is Power Program (KIPP) – have showed positive outcomes for charters.
The result, say education researchers, is a heated debate but also a growing consensus that charters, like regular public schools, vary widely in their quality and that they are at their best when serving a more disadvantaged population.
“It’s not surprising that suburban charter schools don’t do anything, because suburban schools are already pretty good,” says Diane Whitmore Schanzenbach, a professor at the University of Chicago’s Harris School who has studied charter schools in Chicago. “At this point,” she adds, “the literature is still trying to figure out, are charter schools better or not? And arguably, that’s the wrong question to even be asking.” More interesting, Professor Schanzenbach suggests, would be research on what makes some charters more effective.
The Mathematica study began to explore some of those questions, and it found some correlation between better performance and smaller charters and those that used ability grouping in classrooms more than surrounding schools did.
The study looked at the performance of students after they had been at a charter school for a year or two.
Such national studies only highlight the broad differences in what is ultimately a state-driven policy, says Robin Lake, associate director of the Center on Reinventing Public Education at the University of Washington in Seattle.