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CREDO Report Fails to Build Upon Prior Research in Creating Charter School Classification System

BOULDER, CO (September 7, 2017) – Charter Management Organizations 2017, written by James Woodworth, Margaret Raymond, Chunping Han, Yohannes Negassi, W. Payton Richardson, and Will Snow, and released by Center for Research on Education Outcomes (CREDO), assessed the impact of different types of charter school-operating organizations on student outcomes in 24 states, plus New York City and Washington, D.C. The study finds that students in charter schools display slightly greater gains in performance than their peers in traditional public schools, especially students in charter schools operated by certain types of organizations.

Gary Miron and Christopher Shank of Western Michigan University reviewed the report and found CREDO’s distinctions between organization types to be arbitrary and unsupported by other research in the field. This raises concerns about the practical utility of the CREDO findings.

In addition, Miron and Shank contend that CREDO researchers made several dubious methodological decisions that threaten the validity of the study. A number of these problems have been raised in reviews of prior CREDO studies. Specifically, CREDO studies have been criticized for:

  • Over-interpreting small effect sizes;
  • Failing to justify the statistical assumptions underlying the group comparisons made;
  • Not taking into account or acknowledging the large body of charter school research beyond CREDO’s own work;
  • Ignoring the limitations inherent in the research approach they have taken, or at least failing to clearly communicate limitations to readers.

These problems have not only gone unaddressed in Charter Management Organizations 2017, but have been compounded by the CREDO researchers’ confusing and illogical charter organization classification system. As a result, the reviewers conclude that the report is of limited value. Policymakers should interpret the report’s general findings about charter school effectiveness with extreme caution, but might find CREDO’s work useful as a tool to understand how specific charter school management organizations perform relative to their peers.

Find the review, by Gary Miron and Christopher Shank, at:

Find Charter Management Organizations 2017, by James Woodworth, Margaret Raymond, Chunping Han, Yohannes Negassi, W. Payton Richardson, and Will Snow, published by CREDO, at: FINAL.pdf

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