Chart credits: John Butcher
by James A. Bacon
One last set of graphics shedding light on the SOLs… Occasional contributor John Butcher graphed the correlation between 9th-grade reading pass rates and the percentage of economically disadvantaged (ED) children in Virginia’s school divisions. The big-picture conclusion: The percentage of economically disadvantaged children is the dominant variable accounting for a division’s SOL performance, explaining about 57% of the variation between divisions.
But that still leaves 43% left to be explained. Presumably, much of that 43% consists of variables within the school system. Such variables might include spending per pupil, student-teacher ratios, or the quality of teachers and principals.
In the search for clues, it might be worthwhile looking at outlier school divisions that beat and fall short of expectations by wide margins. The gold box indicates the City of Richmond school system, which has nearly 80% disadvantaged students. The City of Richmond school division starts with a big handicap… and goes downhill from there.
Then there’s Lancaster County, standing by itself in the lower, left-hand corner — the worst under-performer in the state. Lancaster has one of the lowest English SOL pass rates despite the fact that only one fifth of its students are disadvantaged. If there are no unique circumstance to explain that difference, the school board and parents need to start asking tough questions.
On the positive side, there are four outliers along the top of the chart. Perhaps we should be asking what those school systems are doing right.
This chart shows the correlation between the math SOL pass rate and the percentage of economically disadvantaged students. Math performance is less closely tied to socio-economic status. The percentage of disadvantaged students in the school division accounts for 42% of the variability, far less than for reading.
Butcher has identified the under-performing outliers in red: Lancaster County (left) and Buena Vista. The green diamonds represent (from left) West Point, Wise and Bristol. As he concludes:
We might wonder why we’re not hearing from [the Virginia Department of Education] about what the outperformers are doing right (or whether they are cheating to get these numbers). VDOE does have a massive (and massively manipulated) accreditation process; I’ve not seen any analysis that would show that it’s doing anything for the underperformers.
