Some charter schools do better than others, and this may be why

A new study concludes that one of the biggest contributions of the most effective charter schools is the extra help many of them give students, important information in Georgia as voters consider whether to change their state constitution in a way that could create more charter schools.

Gov. Nathan Deal is proposing a new state school district that would take over failing schools and, possibly, convert them into charter schools. The referendum on an Opportunity School District will appear on the November ballot. About 90,000 Georgia students already attend a charter school, a number that likely would grow if the measure is approved.

The authors of the paper — "What Can We Learn from Charter School Lotteries?" — compared the performance of students who won a spot at a charter school in an annual lottery and those who did not and had to stay in their traditional neighborhood school. The researchers explored several theories behind the higher achievement of some of those who got in — from the "no excuses" policies prevalent in urban charter schools to differences in class size, spending and teacher certification. They concluded that three explanations rose to the top: the amount of teacher feedback, above-average suspension rates and intensive tutoring. Tutoring had the strongest correlation with accelerated performance.

“This finding about the importance of tutoring is in line with other recent evidence pointing to dramatic gains from intensive tutoring on its own, suggesting a good place to start for effective and practical reform at traditional public schools,” wrote the authors, Julia Chabrier of J-Pal North America, Sarah Cohodes of Teachers College Columbia University, and Philip Oreopoulos of the economics department at the University of Toronto.