The recent state report on 2010-11 dropout rates may have added to confusion over how many Charlotte-Mecklenburg students are staying in school. As one person who emailed me noted, the CMS dropout rate of 3.57 percent seems way out of whack with a 2011 graduation rate of 73.5 percent.
It's not as crazy as it sounds. The annual dropout rate tallied the percent of all high school students who left school in 2010-11. The on-time graduation rate is the percent of students who started ninth grade in 2007-08 and graduated four years later. During those four years, CMS' cumulative dropout rate was 18.6 percent (the rate has been dropping every year).
That's still short of the 26.5 percent who failed to graduate in four years. Some of those no doubt came back this year, neither dropouts or on-time grads. In 2010-11, 454 CMS students who should have graduated with the Class of 2010 got their diplomas, bumping up the total graduation rate for that class by 4.6 percentage points.
I can't swear that there are no mistakes in CMS' drop-out or on-time graduation rates, but there has been no indication that either is faulty. The error that created a stir and led to the resignation of a data administrator had to do with a completely separate measure created by CMS, which tallied the percent of students who had never been retained and used that as a gauge of being on track to graduate.