Can a Few Years' Data Reveal Bad Teachers? The Value of Test Scores Raj Chetty and John N. Friedman, economists, Harvard Like batting averages in baseball, value-added data can be a useful statistic even though it's not perfect. Let's Not Rush Into Value-Added Evaluations Jesse Rothstein, economist, U.C. Berkeley Some teachers are ineffective at first but improve as they age, while others start strong but then burn out. Test Scores Are Only a Snapshot Dawn Shirk, teacher, Reidsville, N.C. Teachers need to be held accountable for 180 days of teaching, not for the one day students were tested. We Know Which Teachers to Fire Lance T. Izumi, Pacific Research Institute The ability to discern good teachers from bad must be accompanied by the power to push out the bad. Results Are In; How Will We Respond? Arun Ramanathan, The Education Trust - West Good teachers get good results. But African-American, Latino and low-income students are far less likely to have access to the best teachers. Use the Data, but Constructively Sydney Morris, Educators 4 Excellence Teachers have always intuitively known that what we do has far-reaching impact. Performance measures should help us to do more and better.