Monday, June 23, 2008

Flawed Research:Vouchers & Special Education

Another piece of flawed research for you to pass on to your teaching peers and refute arguments by voucher supporters.

Florida Voucher Report Too Flawed to be Valuable

Review criticizes report’s conclusion that vouchers have positive impact on special education outcomes

A recent Manhattan Institute report claims Florida’s program of publicly funded, private-school vouchers for special education students improves outcomes for special education students who remain in public schools. A Think Twice review of the report, however, concludes that research design problems and weaknesses in data analysis and interpretation render the report of little value to policy makers.

“The Effect of Special Education Vouchers on Public School Achievement: Evidence from Florida’s McKay Scholarship Program,” was written by Jay P. Greene and Marcus Winters and published by the Manhattan Institute for Policy Research. It was reviewed by Professor John T. Yun of the University of California at Santa Barbara.

Florida’s McKay Scholarship Program provides vouchers for special education students to attend private schools. The scholarship program is open to any Florida student classified as having a learning disability. As of the 2006-2007 school year, about 4.5% of Florida’s special education students received these vouchers though The Manhattan Institute analysis appears to cover an earlier period, from school years 2000-2001 through 2004-2005, during which time the program enrolled fewer students.

The Manhattan report is based on statistical analyses that, its authors conclude, shows that the McKay program spurred public schools to improve achievement for those special education students who remained in public schools during that time. The report presents relatively small effect sizes (a small competition benefit), but asserts that these results are probably understated.

Yun’s review finds the evidence weak. He points out that any contributions the report may make are, “outweighed by research design problems, failure to take into account alternative explanations and unsubstantiated assumptions about the direction of possible selection bias.”
Yun concludes that the report offers policymakers little guidance: “Any attempt to use this report for decision-making or policy evaluation, prior to validation using different methods and more robust approaches, should be viewed with extreme skepticism.”

Find John Yun’s review and the The Manhattan Institute’s report at:

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