Note: Post updated from October, 2018 to correct the 2017 state rate.
The increase in the state rate was driven by an increase in the standard diploma rate. The drop in the Richmond rate came from a 2.7% decrease in the advanced studies rate.
But you, Astute Reader, are still looking at that first graph and asking: “John! You’ve been ranting about how VDOE’s manipulation improved the state rate by about 1.3 points for ‘17 and ‘18 and the Richmond rate by perhaps five points. Where are those increases?”
Ah, what a pleasure to have an attentive reader! The 1.3 and 5 point boosts look to have been offset or partially offset by decreases in the End of Course pass rates.
Turning to the data, here are the graduation rates again along with the averages of the five EOC subject area pass rates.
Students must pass six EOC tests to graduate. Thus, the decreases of the pass rates of those required courses must have lowered the graduation rates. Then the VDOE data manipulation offset those graduation rate declines in some measure.
That looks like a general explanation. The specific would require a more detailed knowledge of which students passed or failed which courses, and where in their four-year journey through high school, and whether they graduated. For sure, the drop in the Richmond pass rates is consistent with the absence of the five-point boost there.
Of course, correlation is not causation and doubtless there are other factors in the mix here. The floor is open for any more convincing suggestion.
BTW: The Big Drops in Richmond, and the lesser in state, EOC pass rates mostly came in math and science.
Preview of Coming Attraction: The Board of “Education” has its next Finagle factor in place: Under the new accreditation regulation (subsection B.3), we now have “locally verified credits” for students who flunk the required SOL tests. This should insure another nice increase in the state graduation rate, paid for by another not-so-nice decrease in student learning.