Earlier this month, the Gadfly reviewed a study of the effectiveness of Teach for America participants and other teachers without full certification in Arizona, a study that we found to be severely flawed. [To read that review, go to http://www.edexcellence.net/gadfly/issue.cfm?issue=42#621.] That study, by Ildiko Laczko-Kerr and David Berliner, found that students of teachers without full certification score lower on tests than students of certified teachers, but the researchers were not able to control for students' prior test scores, leaving unclear whether teachers without full certification are assigned to students who score lower on tests to begin with. Rick Hess, now at the American Enterprise Institute, eloquently dismissed the study in the Progressive Policy Institute's newsletter last week (available at http://www.ppionline.org/ppi_ci.cfm?knlgAreaID=110&subsecid=900001&contentid=250847)
Not satisfied to hear that people who are already skeptical of teacher certification reject the conclusions of the Laczko-Kerr/Berliner study, the folks at Teach for America sought out two analysts with no connection to the debate over teacher certification and asked them to evaluate the study's methodology and the claims made by its authors. These researchers, Paul Freedman of the University of Virginia and Kosuke Imai of Harvard, both found the study unconvincing. A summary of their reviews can be found at http://www.edexcellence.net/gadfly/reports/ASUStudyResponse09_23_02.doc. The review by Freedman is available at http://www.edexcellence.net/doc/freedman_TFA_memo.pdf and Imai's is at http://www.edexcellence.net/doc/imai_TFA.pdf.