NEPC Review Finds Charter School Productivity Report Lacks Validity

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Scholar points out inaccurate use of NAEP results and questionable calculations for spending data.

The sector with the higher percentage of poor pupils scores lower on the NAEP test.

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A recent report from the University of Arkansas Department of Education Reform (DER) on charter school productivity asserts charter schools are more effective in producing achievement on standardized tests and are also less costly per pupil than traditional public schools. A new review released today finds the report’s claims suffer from multiple sources of invalidity, rendering the report useless.

Gene V Glass, Regents' Professor Emeritus at Arizona State University, reviewed “The Productivity of Public Charter Schools” for the Think Twice think tank review project of the National Education Policy Center (NEPC).

The report uses findings from the National Assessment of Educational Progress (NAEP) and “revenues received” to support its claim that charter schools spend less per pupil than traditional public schools and produce achievement as good as or superior to that of traditional public schools.

In his review, however, Glass points out that the report inaccurately employs NAEP test results, and that its calculation of expenditures in charter and traditional public schools relies on questionable data. The report, meanwhile, also discounts the fact that demographic differences between the two sectors are highly correlated with NAEP performance. In short, Glass says, “The sector with the higher percentage of poor pupils scores lower on the NAEP test.”

Taken together, the report’s flaws leave readers with little evidence on which to base any valid conclusions, Glass concludes. He predicts, however, that despite its many shortcomings, charter school supporters will attempt to use the findings to advocate expanded funding for charter schools. In that respect, he writes, “The report continues a program of advocacy research that will be cited by supporters of the charter school movement.”

Find Gene V Glass’s review on the NEPC website at:

Find "The Productivity of Charter Schools" on the web:

The Think Twice think tank review project ( of the National Education Policy Center (NEPC) provides the public, policymakers, and the press with timely, academically sound reviews of selected publications. NEPC is housed at the University of Colorado Boulder School of Education. The Think Twice think tank review project is made possible in part by support provided by the Great Lakes Center for Education Research and Practice.

The mission of the National Education Policy Center is to produce and disseminate high-quality, peer-reviewed research to inform education policy discussions. We are guided by the belief that the democratic governance of public education is strengthened when policies are based on sound evidence. For more information on the NEPC, please visit

This review is also found on the GLC website at

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William Mathis

Gene V Glass

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National Education Policy Center (NEPC)
since: 03/2011
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