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.

In Ward 3, the average student's growth-percentile score on the D.C. Comprehensive Assessment System reading exam over the past two years was 71, meaning that the average student scored better than 71 percent of D.C. students who achieved the same score. Meanwhile, the average student in Ward 7 was performing better than only 44 percent of students who they had been "tied" with.

A growing gap
A recent report shows that, on average, students at the best schools are outpacing their peers at the worst schools on the city's standardized tests.
Average two-year median growth percentile by ward
Ward Math Reading
1 49.2% 54.5%
2 53.3% 53.0%
3 68.6% 70.8%
4 50.6% 50.9%
5 45.2% 48%
6 50.4% 48.1%
7 45.2% 44.4%
8 43.0% 46.0%
Top 5 Schools - Reading
School Neighborhood DC CAS proficiency 2011 Growth scores
Hyde-Addison Elementary School Georgetown 81.2% 79.7%
Murch Elementary School Tenleytown 85.9% 77.7%
Benjamin Banneker Academic High School Pleasant Plains (magnet school) 94.3% 75.9%
Stoddert Elementary School Glover Park 78.2% 74%
Key Elementary School Palisades 87.7% 72%
Top 5 Schools - Math
Key Elementary School Palisades 90.8% 73%
Bancroft Elementary School Mount Pleasant 53.1% 72.3%
Ross Elementary School Dupont Circle 70.7% 72%
Murch Elementary School Tenleytown 85.9% 71.7%
Stoddert Elementary School Glover Park 84.1% 70.2%
Bottom 5 Schools - Reading
Eastern Senior High School East Capitol Hill 7.1% 27.5%
Savoy Elementary School Anacostia 21% 27.6%
Aiton Elementary School Lincoln Heights 21.7% 28.5%
Noyes Education Campus Brookland 31.9% 29.5%
Tyler Elementary School Capitol Hill 28% 30%
Bottom 5 Schools - Math
Drew Elementary School Northeast Boundary 13.3% 23.2%
Johnson Middle School Douglass 17.1% 24.6%
Savoy Elementary School Anacostia 15.4% 25.2%
Aiton Elementary School Lincoln Heights 16.7% 28.6%
Noyes Education Campus Brookland 29% 29%
Note: Growth scores refer to the "median growth percentile," which refer to year-to-year growth on the D.C. Comprehensive Assessment System exams. The numbers are averaged between the growth seen in the 2009-2010 school year and the 2010-2011 school year. For example, a school's MGP of 77.7 percent means the average student scored better in 2011 than 77.7 percent of students citywide who received the same score as the student in 2009. Alternative and special-education schools were not included in these charts.

In other words, the students in the city's poorest schools who were on equal footing with students in the city's top schools didn't stay that way for long.

It's not shocking that good schools produce good results for students. But the gap is still widening as recently as last year, although the D.C. Council and school leaders are throwing an unprecedented amount of resources at improving poorly performing schools.

"These children are being cheated of a quality education," Eve Brooks, a member of the Near Southeast/Southwest Community Benefits Coordinating Council, said about the low-income students who attend Amidon-Bowen Elementary School.

At Amidon-Bowen, only about 39 percent of students outpaced their counterparts across the city on math or reading, but the Southwest Waterfront school is hardly the worst.

Across the Anacostia River, only 23 percent of students at Drew Elementary achieved the same results on the math exam as students they were recently on par with. Just a mile down the road, 28.6 percent of students at Aiton Elementary School keep pace with their peers.

South of the Suitland Parkway, 24.6 percent of Johnson Middle School students achieved the same results as students who had been on similar footing throughout the city on the math test.

On the same test -- but on the other end of the middle-school spectrum -- 64 percent of Alice Deal Middle School students were doing as well or better than their peers within a year. At Key Elementary, 73 percent of students outperformed, putting Key at the top of the list.

Cate Swinburn, chief of data and accountability for D.C. Public Schools, reiterated in an email that the data refers to the past two years and does not dictate future trends. She did not comment on the expansion of the gap between the city's best and worst schools.

Jeff Noel, the director of data management for OSSE, said that because the report examined only 2009 through 2011, the school system could not be sure whether the rate at which the gap was growing was slowing down or speeding up.

But Noel said the disparity has "absolutely" been growing, for a simple reason: "The higher-performing schools are taking students from the same growth levels and taking them to proficiency."