On average, charter schools are not performing as well as their traditional public-school peers, according to a new study that is being called the first national assessment of these school-choice options. The study, conducted by the Center for Research on Education Outcomes at Stanford University, compared the reading and math state achievement test scores of students in charter schools in 15 states and the District of Columbia—amounting to 70 percent of U.S. charter school students—to those of their virtual "twins" in regular schools who shared with them certain characteristics. The research found that 37 percent of charter schools posted math gains that were significantly below what students would have seen if they had enrolled in local traditional public schools. And 46 percent of charter schools posted math gains that were statistically indistinguishable from the average growth among their traditional public-school companions. That means that only 17 percent of charter schools have growth in math scores that exceeds that of their traditional public-school equivalents by a significant amount.
In reading, charter students on average realized a growth that was less than their public-school counterparts but was not as statistically significant as differences in math achievement, researchers said.
"We are worried by these results," Margaret Raymond, director of CREDO and lead author of the report, Multiple Choice: Charter School Performance in 16 States, said at a news conference. "This study shows that we've got a 2-to-1 margin of bad charters to good charters."
Charter schools, free public schools that operate under their own mandate ("charter") rather than the overall district policies, are a staple of education reform agendas across the United States. Supporters say they improve public education by giving parents options and forcing schools to compete for students. The Stanford report already is riling up these schools' most ardent advocates.
The Washington-based Center for Education Reform disputed the findings, saying that they're based on uncorrelated variables, contradictory demographics, and a virtual methodology. The organization said that comparing the test scores of charter-school students to their "virtual" peers in regular public schools—students who match the charter students' demographics, English language proficiency, and participation in special education or subsidized lunch programs—is simplistic and is a fundamental flaw in the research because no two students are the same.
"More than 16 years of charter school research and analysis from CER shows that charter schools are outpacing their conventional public school peers with fewer resources and tremendous obstacles," the nonprofit group said in a news release.
The CREDO report identified five states—Arkansas, Colorado, Illinois, Louisiana, and Missouri—where charter schools had significantly higher learning gains than traditional schools. But the report contended that if charter schools are to flourish, their supporters must be willing to establish accountability in exchange for flexibility. The reluctance to close underperforming charters because of powerful community supporters hurts students and reflects poorly on charter schools as a whole, the report said.
The research comes on the heels of a recent pledge by President Barack Obama's education secretary, Arne Duncan, to use $5 billion of the $100 billion in federal stimulus funds for education to press states on charter schools. "States that don't have charter school laws, or put artificial caps on the growth of charter schools, will jeopardize their application" for federal grant money, Duncan said in a call with reporters last week. Currently, 10 states lack laws that allow charter schools, and 26 others cap their enrollment.
The Stanford report may offer some encouraging news for charter schools: Students in poverty and English-language learners outperformed their public-school peers in both reading and math. However, learning gains for black and Hispanic charter-school students were significantly lower than those of their traditional-school twins. But critics said those results demonstrated the flaws in the Stanford research: The overlap between low-income/English-learner students and black/Hispanic students is so great, CER said, that it should be impossible to get such contradictory results.