Improving teaching effectiveness is a hot topic for policymakers around the country these days. The gathering movement marks an important step forward in the ongoing effort to strengthen our nation's schools. In many cases, however, these efforts start and stop with improving outdated, inadequate teacher evaluation systems. Such approaches fail to…

Researchers demonstrated a quarter century ago that schools could effectively employ value-added statistical methods. At the time, only a few states and districts had accumulated the necessary annual assessment data to take advantage of the breakthrough. Today, every state has the capacity to provide educators with value-added data. Yet most…