Students who were offered scholarships in Washington, D. C.’s voucher program had a higher graduation rate than students who applied but were rejected, the U. S. Department of Education discovered.
The National Center for Education Evaluation and Regional Assistance at the Institute of Education Sciences released a final report in 2010 on the DC Opportunity Scholarship Program which provided vouchers for private education to low-income students in Washington, DC. The study also showed a predicted gain in reading scores after at least four years in the program of 3.9, although the authors cautioned that the result was not statistically significant at the 95th percent confidence interval.
The IES evaluated the success of the program by conducting a statistical comparison of students who received offers of scholarships through the lottery system the OSP provided and those who did not. The study analyzed the changes in test scores and high school graduation rates between the groups after at least four years in the program. The study found that an OSP scholarship offer raised the probability of a student graduating high school by 12 percentage points. The study authors concluded that the results were statistically significant.
The study authors do not conclude that the increase in reading scores is statistically significant, as it was only confirmed by statistical tests to the 94th percent confidence interval. As the Heritage Foundation notes, “Researchers generally require a 95 percent level of confidence to be ‘statistically significant.’”
Michael Watson is an intern at the American Journalism Center, a training program run by Accuracy in Media and Accuracy in Academia.
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