That is a new paper by Will Dobbie and Roland G. Fryer Jr., here is the abstract:
In this paper, we collect data on the inner-workings of 39 charter schools and correlate these data with school effectiveness. We find that traditionally collected input measures—class size, per-pupil expenditure, teacher certification, and teacher training—are not correlated with school effectiveness. In stark contrast, we show that an index of five policies suggested by qualitative research—frequent teacher feedback, the use of data to guide instruction, high-dosage tutoring, increased instructional time, and high expectations— explains approximately 45 percent of the variation in school effectiveness. The same index provides similar results in a separate sample of charter schools.