Are Miami-Dade's Charter Schools Really "Impressive"?

Picking up where I last left off, let's take a look at some test score results from Miami-Dade, FL and see if the charter schools there -- which are, according to the local press, running wild while making their operators boatloads of money -- are really living up to their hype.

For this post, we'll keep it simple (for now): let's leave aside the glaring differences in student populations between the charters and the M-DCPS.

We'll find a way to control for those student differences later; right now, we'll just take a look at test score measures between the charters and the non-charters. Let's start with reading:

The FCAT is Florida's state-wide standardized test, given in grades 3 through 10. What I've done here is calculate the weighted mean, or average, score for either charters or non-charters as a group across Miami-Dade. The FCAT uses a "developmental scale score," which allows for comparisons of scores over time; in other words, we would expect the scores to rise from grade to grade.

There's no doubt: the charters get better overall average scores on the FCAT reading test. Except...

Notice how the non-charters keep pace with the charters through the progression from Grade 3 to Grade 10, even though the non-charters started behind. I find this quite telling: if the Miami-Dade charter sector, as a whole, was giving better instruction, why wouldn't the gap between the charters and non-charters increase with each passing grade?

It's actually a far more complex question than it may appear on the surface, having to do, in part, with the "normalizing" of the tests. Still, I'd argue we're not seeing much evidence here that the charters are getting gains that compound over time. In fact...

This is a different way to measure test-based outcomes: the percentage of students who "clear the bar," or score above a cutoff point that shows proficiency (in Florida, that's "Level 3"). Again, there's no doubt: the charters do have more kids who clear the bar (remember, however: they don't serve the same types of students).

But look at the gap between the public schools and the charters as we go through time:

What starts as a 13-point gap in proficiency in Grade 3 shrinks to a 4-and-a-half-point gap by Grade 10. Notice that the gap shrinks considerably in high school: do dropouts contribute to this collapse?

Again, this is a more complex issue than it may appear on the surface. But my point is this:

• We know that the charters don't serve as many students, proportionately, who are in economic disadvantage, are Limited English Proficient, or have special needs.
• At the earliest testing grades, the charters enjoy their widest gap in student achievement with the public schools: very likely, this is due to the fact that they don't serve the same types of kids.
• As the years progress, the public school students show comparable growth in test based measures to the charters.
• And the gap between charters and publics shrinks considerably as the students age.

Is this "impressive"? I suppose that's a matter of opinion; let's take a look at math before I give mine.

Again, non-charter students start behind, but they move up in parallel with their charter peers. In 8th Grade, the FCAT scores go down, but that's likely because 8th Grade algebra students, who are going to be the better math students, are taking the End Of Course (EOC) exam for Algebra, and not the FCAT (I've looked for confirmation of this, but haven't found it yet).

In fact, there are two Florida EOC courses in math: Algebra and Geometry. Here's how the charters compare to the non-charters:

On tests that are on a scale from 325 to 475, the difference between the average charter and non-charter student in Miami-Dade in high school math is less than 2 points.

Here are the proficiency rates:

And here's the "gap" in those rates:

Again: what's likely happening in Grade 8 is that the more mathematically advanced students are not taking the FCAT, but instead the EOC Algebra test (of course, that's also true for the charters). We have a much less smooth decline in the gap here compared to the reading proficiency rates. The high school courses, however, tell much of the story: the charter "advantage" in high school math is, for all intents and purposes, non-existent.

What are we to make of all this? Maybe it's best to look at the charterization of Miami in terms of cost and benefit:

COST:

• Hundreds of millions of taxpayer dollars diverted to private company profits, instead of being put into the classroom.
• A charter sector that educates far fewer students with special needs or who live in economic disadvantage, leaving the public schools to pay for students who are more difficult and more expensive to educate.
• The abrogation of the rights of families who send their children to charters.

BENEFITS:

• A few extra scale score points on tests -- but no evidence of sustained differences in student achievement over time compared to the public schools.

Me? I'm just not seeing it. Even if you want to get small test score gains by segregating your student populations -- a dubious proposition to begin with -- why give millions of dollars to charter operators? The small gains just don't seem to be worth the big costs.

More to come...

Maimi charter school edu-preneur and Academica business partner Pitbull.