The study, released this past Tuesday, by Stanford University researchers at the Center for Research on Education Outcomes, examined the standardized test results of students enrolled in charter schools in 25 states, the District of Columbia and New York City. The charter school results were compared with those of students with the same demographics and academic profiles in public schools that the charter students would have otherwise attended.
The original study, conducted four years ago, showed that only 17 percent of charter schools managed to raise student math test scores above those of local public schools. The new report said that 29 percent of charter schools performed better in math than local public schools.
The study concluded that charter schools, which are typically given more freedom to design curriculum and hire nonunion teachers than traditional public schools, range widely in quality from state to state.
While charter schools on average produced better results in states including Louisiana, Massachusetts, Michigan, New Jersey, New York, Rhode Island and Tennessee, as well as Washington, D.C., in some states, including Arizona, Nevada, Ohio, Pennsylvania and Texas, the results were worse — in some cases, significantly worse. Source