With over a decade of data, now can answer quite a few questions about the billionaire-led so-called education reform that has shuttered so many schools, atomized low-income neighborhoods that used to be centered around their local schools, created so much churn in the teaching profession, and turned many urban schools into all-test-prep, all the time.
We can now tell whether students are actually learning more on national tests like the NAEP (National Assessment of Educational Progress) as a result of No Child Left Behind, Race to the Top, and the Common Core.
Along with many other researchers and commentators, I have been showing repeatedly, on this blog, that the answer is, “No.”
My latest piece of evidence comes from two sources: the NAEP Trial Urban District Assessment (TUDA) test scores for 21 urban school systems published by the National Center for Educational Statistics (NCES), and data on the percentages of students enrolled in charter schools in those cities, published by the National Alliance for Charter schools.
We have been repeatedly told that more charter schools means better education for all; supposedly the competition with the charter schools will cause the regular public school systems to improve dramatically as well.
So if you plot the “market share” of charter schools in a bunch of cities against their NAEP math or reading scores in the 4th or 8th grade, you should see a strong positive correlation, something like the data I invented in the graph below:
Well, it happens to be the other way around.
We do not see strongly focused scatterplots with linear correlations going up and to the right.
We instead see strong trendlines going DOWN and to the right.
Yup, for the 17 cities that NAEP TUDA and the National Alliance for Charter Schools both have data, for these 17 large cities, the higher the fraction of charter schools, then the worse the kids in the public schools do on the NAEP in 4th and 8th grade reading and math.
This greenish scatterplot has the “market share” of charter school students in these 21 cities on the y-axis on the left, and the NAEP grade 4 math average scale score for that entire city along the x-axis on the bottom. It’s quite clear that higher NAEP scores are linked with lower charter school enrollments.
In the graph above, the value of R-squared is 0.454, and the value of R (the coefficient of correlation ) is 0.6738. For completeness, I also plotted the average score for all US urban students (238) and he average for all US public school students (241). The topmost blue dot on the left represents Detroit, and the next highest dot, at about 43% market share, is Washington, DC. The dot near the bottom center at a NAEP score of 220 is Fresno. The system at the very bottom, with a score of 234, is Louisville KY (aka Jefferson County).
In the next graph (tan/blue), we see the exact same data, only for 8th grade:
In this one, R is almost 0.7, and R-squared is about 0.49, both quite strong correlations.
The very alert reader may notice that this is the graph that I used to make up some phony statistics that DO NOT EXIST but are predicted by many pundits who haven’t been in a public school classroom for a very long time.
My final graph for today shows the same thing, but for 8th grade reading.
All of the correlations have been rather strong, but this one is the strongest of all.
Of course, correlation isn’t necessarily causation. We don’t know from the data alone which factor causes the other, or if there is a third factor causing both changes.
But in any case, the argument that charter schools and choice — as defined by Gates, Wallton, Rhee and Duncan — would inherently lift all boats is definitely demolished.