NYU Steinhardt News

Corcoran Weighs in on City's Plan to Rate Teachers Using Value-Added Model

Sean Corcoran, assistant professor of educational economics and affiliate of the Institute of Education and Social Policy, weighs in on the current controversy surrounding New York City's plan to release teacher ratings using a value-added model.

In an interview with City Limits magazine, Corcoran points out that the city's plan to release the scores of approximately 12,000 teachers ignores the vast majority of teachers, since value-added scores are only calculated for teachers with more than 2 years of teaching history, for teachers of math and reading, and for teachers in grades 4 through 8.

Value-added scoring, a technique developed by economists at Columbia University, assesses teachers based on the gains their students make on standardized tests over time. Corcoran's own research in collaboration with the Annenberg Institute for School Reform has demonstrated that value-added scoring can be markedly inconsistent. Teachers who rank in the top percentile one year may find themselves ranked in the bottom the next.

The problem, as Corcoran sees it, is that the methods have been developed by researchers with no education experience.  

"Economists and statisticians devised the value-added method, advised by policy experts with law and business backgrounds," he told City Limits. "Cognitive development experts have not been part of this process since day one."

To read the entire City Limits article, click here