Charter schools still in question.

When the National Assessment of Educational Progress testing results revealed last year that fourth graders in charter schools performed at lower levels than their public school peers in reading and math, charter school officials said the reason lies in that more economically disadvantaged students are in charter schools than public ones. But a new study says that simply isn't so.

The study, released by the Economic Policy Institute and Columbia University Teachers College, shows that while charter schools enroll a higher percentage of black students than regular public schools, black students in charter schools are less likely to be eligible for lunch subsidies than those in public schools.

"I am convinced that except in a couple of places, public schools serve a lower socioeconomic class of kids than charter schools. There is no evidence that charter students start at a worse place than public school students," says Martin Carnoy, a professor of education and economics at Stanford University and a co-author of the study.

The study, based on additional data from NAEP, shows that students in charter schools perform at levels that were no higher--and in some cases consistently below--their counterparts in public schools.

Andy Smarick, director of Charter School Leadership Council, says the studies still fail to note that charter schools are improving the achievement of low-level students.

He says educators should consider the source of the study before jumping to conclusions.

"EPI is funded by unions and they have an agenda against charter schools," Smarick says.

But the two sides do agree on one issue: They both say the best way to measure student growth and achievement is to consider where each student has started, not just whether they reach a certain proficiency level.