Gap between best and worst D.C. schools growing

The gap between the District’s best- and worst-performing schools has been growing amid the most intense school reform in the city’s history, according to a report commissioned by the Office of the State Superintendent of Education.

The report calculates a “median growth percentile” for each school, which measures students’ annual growth against similar students across the city. The American Institutes for Research found that, if two students have the same test scores in 2010, but one attends a wealthy, high-performing school and the other attends the opposite, the student at the wealthy school likely would have outpaced the latter student substantially in 2011, even though they were on equal footing the year before.