Following months of pressure from states and education groups, U.S. Secretary of Education Margaret Spellings has announced a pilot program that will let some states use what are known as growth models to evaluate the success of schools and districts under the federal No Child Left Behind Act. Growth models track the progress of youngsters over…

This article reports how "value-added" measures that track the "value" that schools add to individual students' learning over time are increasingly popular with educators and policymakers. Some view the methods as an antidote to accountability systems that focus solely on getting children to a specified achievement level on a state test,…