IT IS UNDERSTANDABLE that the D.C. public school system gets most of the attention when student test scores are released, given the high-profile efforts to reform the traditional public schools. What gets overlooked, though, is the equally compelling story of the progress being made by the city’s public charter schools. Results from this year’s testing are real cause for celebration, with charter students throughout the city showing impressive gains in both reading and math.

Final results of the 2011 District of Columbia Comprehensive Assessment System were released last month and, for the first time, charter schools approached or exceeded the 50 percent milestone of students who are proficient or advanced in both reading (49.9 percent) and math (53.7 percent). Just five years ago, only 40 percent of students were proficient in math and 43 percent proficient in reading, so the gains are considerable. Also encouraging is that 60 percent of the charter school campuses — 44 of the 76 tested — posted higher scores this year than last.

Of course, just as in the public school system — where less than 50 percent of students are proficient in reading and math — there is still much work to be done. But the steady progress by the charters suggests that the systems and policies are in place that can result in good outcomes for children. Here, the D.C. Public Charter School Board deserves credit for its insistence on successful outcomes. The board’s willingness to shut down schools that don’t perform — more than a third of schools since the start of charter reform — not only weeds out failing schools but helps set the bar higher for those that stay open. With an enrollment of 30,000 students, charters serve about 40 percent of public school students in the District.

Particularly striking was the performance of charters serving neighborhoods in economic distress; in some cases those schools actually outperformed schools in more affluent areas of the city. At Achievement Preparatory Academy Public School in Ward 8, for example, 85 percent of students are economically disadvantaged, but 87 percent were proficient in math and 75 percent were proficient in reading. Those are among the city’s top scores. Consider that students at Thurgood Marshall Academy and KIPP DC College Preparatory Academy in Ward 8 outperformed Wilson Senior High School in Ward 3.

No doubt such practices as KIPP’s extended school day or the flexibility of charters in hiring are important factors, but don’t discount the hard work of teachers and students singularly focused on learning. Such achievement should be a rebuke to those who would use family income or troubled surroundings as excuse for why students cannot learn.