Review finds Pro-voucher Polls Plagued by Biased Questions and Sampling Problems

Contact: Teri Battaglieri, (517) 203-2940;
Jon Lorence, (713) 743-3959;
A. Gary Dworkin, (713) 743-3955;

EAST LANSING, Mi., (December 2, 2008)—A series of reports based on public opinion polls in 10 states claims that state political candidates could increase their electability if they support school vouchers and other school-choice measures. A Think Twice review of the reports, however, finds that the polls on which they rely contain poorly worded, biased questions and suffer from sampling problems.

The states surveyed thus far are Arizona, Florida, Georgia, Idaho, Illinois, Maryland, Montana, Nevada, Oklahoma, and Tennessee, and the reports were published by the Friedman Foundation for Educational Choice, a think tank that promotes school-choice proposals, including taxpayer-funded private-school vouchers. They were reviewed by professors Jon Lorence and A.Gary Dworkin, both of the University of Houston.

The 10 reports conclude that voters view public schools as performing unsatisfactorily, that they prefer private over public schools, that public funds should be available so parents can send their children to private schools and that potential voters are more likely to support candidates who back school choice proposals such as vouchers.

Lorence and Dworkin note that none of the reports cite any other surveys or research literature regarding opinions on vouchers or on public, private, or charter schools. By comparison, the reviewers cite a series of Gallup polls, conducted annually for Phi Delta Kappa, that include questions measuring public support for private-school vouchers and for public education in general. Those surveys consistently find less support for voucher proposals than shown by the Friedman surveys. In fact, the Gallup surveys consistently show that more Americans oppose vouchers than support them.

In addition, the reviewers point to a number of other factors which might explain why the Friedman surveys yielded more favorable results for school choice proposals.

First, they note that that the population samples surveyed might not represent the voting populations of their states nor the population of parents for whose children school vouchers are intended. Information to establish sampling accuracy is largely missing from the reports, and in at least one of the three instances where sufficient data were provided, the low response rate raises a red flag about possible sample bias.

Additionally, Lorence and Dworkin found repeated instances in which the wording of questions appeared likely to bias the results. These questions appeared to be worded in ways to encourage respondents to favor private-school funding. The reviewers use the corresponding Gallup questions to highlight these problems with wording. Additionally, the survey questions in some instances used terms not widely understood, such as questions about proposals to grant tax credits to companies that finance private school scholarships (vouchers).

“Had the respondents been presented more neutral questions about tax credits and vouchers, the findings may have been less favorable towards these issues,” the reviewers write.

Lorence and Dworkin observe that the 10 papers reviewed are aimed at driving a pro-school-choice agenda through the promotion of tax credits, vouchers, and charter schools. They conclude that the reports should not guide policy and recommend that policymakers avoid relying on, “public opinion surveys that present beliefs as fact,” and encourage them to, “examine research investigating whether charter schools and vouchers actually increase student achievement and other important outcomes.”

Find the review by Jon Lorence and A. Gary Dworkin on the web at:

About The Think Twice Project
The Think Twice project provides the public, policy makers and the press with timely, academically sound reviews of selected think tank publications. It is a collaboration of the Education Policy Studies Laboratory at Arizona State University and the Education and the Public Interest Center at the University of Colorado at Boulder and is funded by the Great Lakes Center for Education Research and Practice.


The mission of the Great Lakes Center is to improve public education for all students in the Great Lakes region through the support and dissemination of high quality, academically sound research on education policy and practices.

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