Class Size less important than teacher feedback and use of data for improving effectiveness


According to a Harvard University paper on New York Charter schools- Getting Beneath the Veil of Effective Schools: Evidence from New York City (November 2011)- evidence on the efficacy of market-based reforms, such as school choice or school vouchers on the one hand and   reforms seeking to manipulate key educational inputs  on the other, have, at best,  had a modest impact on student achievement . Indeed, the data suggest that increasing resource-based inputs may actually lower school effectiveness.

The authors look in detail at 35 New York Charter schools. Charters  were created in the USA  to,  firstly,  serve as an escape hatch for students in failing schools, so most are in disadvantaged areas, and, secondly to use their relative freedom to incubate best practices to be infused into traditional public schools.

Consistent with the second mission, charter schools employ a wide variety of educational strategies and operations, providing dramatic variability in school inputs.

This paper collects data on the inner-workings charter schools and correlate these data with credible estimates of each school’s effectiveness.

The authors find that traditionally collected input measures – class size, per pupil expenditure, the fraction of teachers with no certification, and the fraction of teachers with an advanced degree – are not correlated with school effectiveness. In stark contrast, they  show that an index of five policies suggested by over forty years of qualitative research – frequent teacher feedback, the use of data to guide instruction, high-dosage tutoring, increased instructional time, and high expectations – explains approximately 50 percent of the variation in school effectiveness. The results, they claim,  are robust to controls for three alternative theories of schooling: a model emphasizing the provision of wrap-around services, a model focused on teacher selection and retention, and the “No Excuses” model of education. They conclude by showing that ‘ our index provides similar results in a separate sample of charter schools. Moreover, we show that these variables continue to be statistically important after accounting for alternative models of schooling, and a host of other explanatory variables, and are predictive in a different sample of schools.’

The authors state ‘While there are important caveats to the conclusion that these five policies can explain significant variation in school effectiveness, our results suggest a model of schooling that may have general application. The key next step is to inject these strategies into traditional public schools and assess whether they have a causal effect on student achievement.

Getting Beneath the Veil of Effective Schools: Evidence from New York City

Will Dobbie; Harvard University; Roland G. Fryer, Jr.; Harvard University and NBER


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s