The findings suggest that charter schools are slightly outperforming traditional schools and that to meet ambitious improvement goals, city school leaders will have to make greater strides over the next five years than they have in the past five, a period of rapid and wide-ranging reform efforts.
“We still have a long way to go to see citywide performance go up,” said Soumya Bhat, the study’s author. “That theme is consistent.”
Public officials often assess school progress by tracking the average scores of students in charter schools, in traditional schools and citywide. Between 2008 and 2012, the share of all D.C. students proficient in math and reading rose five points, from 42 percent to 47 percent.
Bhat instead examined the trajectories of individual schools. Using the results of annual standardized tests at 152 schools that existed in both 2008 and 2012, she analyzed the share of students who scored proficient or advanced at each school. She then tracked how the median school — the one squarely in the middle of the pack, with the same number of schools doing better and doing worse — performed.
Citywide, that middle-of-the-pack performance did not improve over the past five years, dropping slightly from 41.8 percent to 41.2 percent.
Proficiency rates at the median charter school rose from about 44 percent in 2008 to about 50 percent in 2012. At the median traditional school, proficiency rates fell from 40 percent to 37 percent over the same period, chiefly because of declines in reading.
Bhat said those numbers suggest the traditional school system might need to consider substantial changes to boost achievement, particularly at the 40 lowest-performing schools, where the goal is to raise proficiency rates by 40 percentage points by 2017.
School system spokeswoman Melissa Salmanowitz was provided with an advance copy of Bhat’s analysis. She said officials could not comment, because they have not had an opportunity to fully review the data.
Median school proficiency rates dropped in poorer parts of the city, including east of the Anacostia River and east of Rock Creek Park in Wards 4 and 5. They rose across Wards 1, 2, 3 and 6, which include the more affluent Upper Northwest and Capitol Hill neighborhoods.
The study points out that performance trends varied widely within every category of school. Since 2008, proficiency rates have risen significantly — by at least five percentage points — at about one-third of all traditional and charter schools. They have declined by that much at another one-third of schools. And one-third of the city’s schools have had modest changes of less than five percentage points.