That report on New York City’s charter schools continues to draw media attention. The Washington Post, in a Sunday editorial, goes so far as to say that the report “demolishes the argument” that charter schools cream the best students from traditional public schools. It also says:
This evidence should spur states to change policies that inhibit charter-school growth. It also should cause traditional schools to emulate practices that produce these remarkable results.
That kind of enthusiam might be a little premature. New York is just one city—and one that charter school experts tell me is known for the quality of its authorizing system for charter schools. What’s more, the promising practices that the report identifies were merely linked to higher student achievement. Even study author Caroline M. Hoxby points out that her findings don’t suggest that things like longer school days, performance pay, or strict classroom management caused the charter school students to outperform their peers in traditional schools.
Some of the excitement over Hoxby’s findings stem from her choice of study design. Hoxby used a randomized control trial to compare the achievement of students who won a charter-school seat in a lottery to that of students who applied but failed to land a spot. Experts consider this methodology to be the “gold standard” for research on effectiveness, but, as this blogger points out in a blog called—what else?—"More Thoughtful,” even randomized studies have their limitations.
There’ve been lots of comments, too, in the blogosphere about Hoxby’s penchant for finding positive results in studies involving free-market education strategies. That may be cause for skepticism, I say, but is it a good enough reason to dismiss the new findings out of hand?