Flat scores, Pt 2: Crunching the numbers

This is a follow-up to my last post about how the lack of growth in US high school scores on the NAEP and decreases in the SAT could be a product of lower dropout rates and increased college opportunities. This would be a pin to the bubble of mostly conservative education reform advocates who are taking last week's release of SAT scores as a new mandate for reform efforts focused on US high schools:

But high schools have been very successful in increasing graduation rates. We know that this has a negative effect on test scores; students most likely to drop out of high schools are among the lowest performers on achievement tests, so test scores go up when these students drop out instead of taking the test and go down when students stay in school and take the tests. The question is whether this is enough to account for overall stagnation in the scores of 17 year-olds on the NAEP.

Here's the table of NAEP results from Michael Petrilli's Fordham article:



The table shows that from 2004 to 2012, math achievement increased by 8 points for nine-year-olds (4th grade), 5 points for thirteen-year-olds (eighth grade), but just 1 point for seventeen-year-olds (12th grade).