The US Department of Education reported that the high school graduation rate rose to another historic high.

The rate represents those who graduated in four years. It does not include those who graduated in August or took five years to graduate. The overall graduation rate of the population 18-24 is higher than the four-year rate. Sometimes I think it was set at precisely four years to make the schools look bad. Personally, I think both rates should be reported at the same time: the four-year rate and the rate for the group 18-24, which shows a truer picture.

It should also be noted that the pressure to raise graduation rates as a marker of success may have inflated the graduation rate through such dubious means as “credit recovery,” in which students who failed a course may get full credit by taking a short-cut program, often online, often fraudulent in terms of learning.

It should also be noted that the District of Columbia has the lowest graduation rate of any state (DC is reported in federal data as both a state and a city). DC is widely hailed as one of the stars of the corporate reform movement. It has been under mayoral control since 2007, when Michelle Rhee took charge as chancellor. Bill Gates once said it would take a decade to know if “this stuff” works. The clock is ticking. Maybe he meant to say two decades or three.