Study Inconclusive About D.C. School Reform

A new independent study said there's no evidence that mayoral control of D.C. public schools has been a factor in improving student performance.

Former Mayor Adrian Fenty took over the school system in 2007 and installed Michelle Rhee as chancellor. She implemented aggressive reforms -- closing schools, firing teachers deemed ineffective by principals and offering financial rewards for teachers who boost their students' test scores. Rhee stepped down after Mayor Vincent Gray was elected last year.

A report released Friday by the National Research Council said it's too soon to draw sweeping conclusions about the effectiveness of the recent reform efforts.

Researchers say a "modest improvement" in test scores over the past four years may not be linked to school reform and could result from demographic shifts.