Charter School Productivity Report Lacks Validity

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.”