Photo of graduation cap from Shutterstock.

Graduation rates vary a lot among DC’s high schools. A series of graphics from the DC government shows just how different they can be.

DC Public Schools had an overall four-year graduation rate of about 58% last year, up by only two percentage points from 2013. And the overall rate for the charter sector fell almost seven points, to 69%.

To calculate the rate, statisticians divide the number of high school graduates in a class by the number of students who entered as 9th-graders four years earlier, with adjustments for students who transfer. Having a four-year rate helps standardize the high school graduation data, but it’s not clear we should expect all students to graduate in four years.

Image from DC Office of Revenue Analysis.

Selective DCPS schools push up the average for the sector

The graphic above, which came from DC’s Office of Revenue Analysis, shows that five DCPS schools that are selective in their admissions pulled up the average significantly for the traditional public school sector. All had graduation rates over 90%.

The next two highest rates within DCPS are for Columbia Heights Education Campus, which also requires an application for admission, and Wilson High School, which has the highest number of affluent and white students of any neighborhood DCPS high school.

The other DCPS neighborhood high schools are clustered towards the bottom of the spectrum, with rates ranging from 39% at Anacostia to 62% at Roosevelt. (Washington Metropolitan and Luke C. Moore are both alternative schools, while Eastern will graduate its first senior class this year.)

The graphic also allows you to see graduation rates for different subgroups of students at a school, and doing that can change a school’s ranking. If you select for special education students, for example, you find that the top-ranked school is a charter, Friendship Collegiate. You can access the full range of graphics here.

Image from DC Office of Revenue Analysis.

Most of the DCPS selective schools aren’t listed in this version of the graphic, because they had fewer than 10 students scheduled to graduate in the special education category.

Other filters reveal discrepancies in the graduation rates for subgroups within schools. At Wilson, for example, the graduation rate for white students is third in the District, at 90%. But for black students, Wilson is in 14th place, with a rate of 76%.

The graphic also shows that only three schools in DC had more than 10 white students graduating last year, all of them DCPS schools: Wilson and two selective schools, School Without Walls and Duke Ellington. Wilson is the only school that graduated 10 or more Asian students.

Changes in rates over time

Another set of graphics shows how four-year graduation rates have changed at each school over the last four years for various subgroups. Wilson’s data, for example, shows gains for black students but decreases for special education and a mixed record for Hispanic students.

Image from DC Office of Revenue Analysis.

A longitudinal view can also reveal ups and downs in a school’s overall rate. DCPS has highlighted the 16-point jump in the graduation rate for H.D. Woodson from 2013 to 2014. But the rate in 2011 was only three points lower than the rate for 2014.

Image from DC Office of Revenue Analysis.

While the charter sector’s graduation rate is still well above DCPS’s, a seven-point drop seems significant. The executive director of the DC Public Charter School Board told WAMU that the board is looking into reasons for the decline, but he noted that the schools with the lowest rates closed last year or will close at the end of this year.

On the other hand, two of the charter sector’s highest-performing schools had double-digit declines. The graduation rate dropped from 96% to 85% at Washington Latin, and from 95% to 85% at KIPP DC College Prep.

Smaller cohorts and greater rigor in charters may explain lower rates

Martha Cutts, the head of Washington Latin, doesn’t see the decline as cause for concern. Some classes are simply not as strong academically as others, she said, and when you have a small cohort a few kids can make a big difference.

In Washington Latin’s case, the original 9th-grade cohort was 54 students, and 46 of them graduated in four years. In an email, a spokesperson for KIPP DC made a similar point, noting that there were only 69 seniors in the class of 2014. (Disclosure: I have contributed financially to KIPP DC.)

Both schools also noted that a number of students who didn’t graduate in four years are on track to graduate next year. Cutts said that she expects three students to do so, and KIPP DC anticipates that the five-year graduation rate for its 2014 cohort will be close to 90%.

For the charter sector as a whole, the five-year graduation rate is 80%, an increase of 11 points over its four-year rate. While the DCPS five-year rate is also higher than its four-year rate, the difference isn’t as large: 63%, an increase of only five points.

For the last several years, education officials have focused on reporting how many students make it through high school in four years, partly due to a federal effort to standardize the way different states report graduation data.

It’s certainly important to compare apples to apples. And it’s important that students stay on track to graduate. On the other hand, high school is not a race. What students learn is at least as important as whether they finish “on time.” And without any high school exit exam in DC, it’s hard to know whether a graduate of one high school really has the same qualifications as someone who has graduated from another.

According to KIPP DC, one reason for the dip in its four-year graduation rate is that the school has increased the rigor of its program after “receiving feedback” from their alumni. “Ultimately we want our students to be well prepared to tackle the challenging coursework that awaits them in college,” a spokesperson said.

Of course, not all DC high school graduates are headed to college, and perhaps not all of them should be. But a high school diploma should at least certify that a student has mastered high-school-level material, even if it’s taken him longer than four years to do that.

Correction: Based on information from the DC Office of Revenue Analysis, the original version of this post said that the subgroup data didn’t include schools with fewer than 25 students in a given category who were scheduled to graduate. Later that office contacted us to say the correct figure was not 25, but 10. We have changed the graphs and text to reflect that information.

Natalie Wexler is a DC education journalist and blogger. She chairs the board of The Writing Revolution and serves on the Urban Teachers DC Regional Leadership Council, and she has been a volunteer reading and writing tutor in high-poverty DC Public Schools.