(Guest Post by Matthew Ladner)
Quick post just to note that the outlines of the story remains broadly similar whether you measure cohort NAEP gains as percentage increases or simply as scale points gained: AZ statewide still leads the field, AZ charters still beats the field like what Clubber Lang did to Rocky in their first encounter in the ring, Michigan charters still edge Louisiana charters, Maryland still needs to invest in ammo and a fortified island complex in hopes of surviving the nuclear zombie apocalypse. The main storyline here is that like the Credo report finding Detroit and New Orleans neck and neck, NAEP finds a similar result in 2011 to 2015 cohort gains for Louisiana and Michigan charters.
The question of which measure is better seems debatable imo so it is easier to simply present both.
Jay P. Greene's Blog 