Striking a blow for vouchers and against the statistical illiteracy of the MSM, Greg Forster of the Friedman Foundation for Educational Choice takes on the latest voucher-appraisal data from the DOE over at Pajamas Media. Turns out that the good reporters over at the Washington Post need remedial statistical education:
So the study shows that the voucher students did better. It just isn’t able to say with a high level of certainty that the vouchers are the reason they did better.Adding insult to injury, the results just barely missed the conventional cutoff for reporting results with high confidence. The standard procedure is to report results if they are 95 percent certain. The results in this study were 91 percent certain. And this is the second year in a row the D.C. results have come close to the cutoff without reaching it.
Eventually, enough 91%-certain results can be aggregated to get over the magic 95% threshold, but the fact is that 95% is arbitrary, leaving a 5% uncertainty. People take flyers on educational systems that have a far less than 91% recommendation going for them, after all.
While the blog's not all about the campaign, in this case, I'll point out that there's actually a candidate in District 6 who understands this...
