Studies That Grade Charter Schools Rely on Imperfect Math
Charter schools are getting very confusing report cards.
Researchers have assessed the thousands of charter schools that have opened around the U.S. in the last two decades. The results from those studies are starting to flood in. But policy makers hoping to learn whether these scholastic experiments have been successful will be disappointed: Some studies say charter schools are outperforming their traditional counterparts. Other studies put charter and conventional schools on par, or even show charters trailing their peers.
The chief explanation for the lack of consensus is that the prominent studies on charter schools rely on different methodologies—all of which have flaws.
Education researchers face a big challenge: how to separate the results of charter schools' educational techniques from the quality and motivation of the students themselves. So far, scholars have been only partially successful at making this distinction, other education experts say.
To study charters, researchers typically measure how well students score on standardized tests compared with their peers at nearby traditional public schools. And head-to-head comparisons give charters a big edge. In 2007, for instance, charter schools in Georgia had graduation rates
