Dropout data: We absolutely must get this stuff right

From today's Baltimore Sun:

More students graduated from the Maryland's public schools last June than in any time in memory, but the high school dropout rate also increased slightly.

Confused by how the graduation rate and the dropout rate could both be on the rise? You're definitely not alone — and it's a shame that Sun reporter Liz Bowie has failed to clarify what is going on here.

So we'll do it for her:

Yes, it's true that a century of physics was thrown on its ear this week when scientists at CERN, the giant particle accelerator near Geneva, announced that they had observed streams of neutrinos traveling faster than the speed of light. But as far as we know, basic mathematical concepts haven't been effected. One plus one is still two. And when you take something away from a group (dropouts, for instance) the remainder (graduates) should be less, not more.

But here's what's happening: Most states calculate dropouts (those who leave school for reasons other than a move to another school or death) differently than graduates (those who complete high school in a requisite number of years — generally four.) What remains are students who are still in school but haven't finished with their cohort.

Ergo, even though the dropout rate generally goes down when the graduation rate goes up, the two numbers can sometimes move in the same direction, up or down. 

In keeping with The Sun's promise to its readers — "Light for All" — Bowie really should have done a better job of explaining this. But in her defense, she's not alone: Many reporters fail to explain the difference in how these rates are calculated. 

And that's a shame, because our nation's citizens can't afford to be confused about the dropout epidemic, which contributes to under-employment, joblessness, criminality and intractable reliance on the country's social service safety net.