Why Does VDOE Use Biased Data to Accredit Our Schools?

VDOE has an elaborate scheme to accredit (or not accredit) Virginia’s schools.  The basis is SOL pass rates (plus, for high schools, the graduation rate that depends on passing at least six end-of-course SOL tests).

But we know that the SOL is influenced by economic status.  For example, here are the 2015 reading pass rates by division vs. the percentage of economically disadvantaged students in the division.

We’re not here to discuss whether this correlation suggests that more affluent families live in better school districts, whether their children are better prepared for school, whether their children have higher IQs, or whatever.  The point here is that more affluent kids will show better SOL scores than less affluent students.

That’s only part of the problem with accreditation.  VDOE adjusts (I would say “manipulates”) the accreditation data in secret ways that mostly boost the scores.  In one case, that manipulation converted a 76.3 and a 73.7 into “perfect scores” and embarrassed the Governor.

So it’s no surprise that VDOE has not used, and now is abandoning, a measure of student progress that is insensitive to economic advantage or disadvantage and that might even be resistant to manipulation, the Student Growth Percentile (“SGP”).

VDOE says:

A student growth percentile expresses how much progress a student has made relative to the progress of students whose achievement was similar on previous assessments.
A student growth percentile complements a student’s SOL scaled score and gives his or her teacher, parents and principal a more complete picture of achievement and progress. A high growth percentile is an indicator of effective instruction, regardless of a student’s scaled score.

VDOE calculated SGPs in reading, math, and algebra for at least three years, ending in 2014. Then they abandoned the SGP for a new measure that looks to be coarser than the SGP. 

VDOE says that the new measure might be useful in the accreditation process because it allows “partial point[s] for growth,” i.e. another way to boost the scores.  There is no mention of sensitivity to economic disadvantage.

How about it, VDOE?  Does your dandy new measure of progress cancel the advantage of the more affluent students?  And if it does, will you use it to replace the SOL in the accreditation process?