(Guest Post by Matthew Ladner)
Tom Patterson recently wrote a column about Arizona NAEP scores, and stated that Arizona had the highest overall gains in combined Reading and Math scores between the 2015 8th grade scores and the same cohort of students 2011 scores as 4th graders. I decided to check it out.
NAEP has been following an odd number year cycle, meaning that the four-year gap between the same cohort of student can be measured. In this case, I took the statewide 2015 Math scores and subtracted from them the statewide 2011 4th grade math scores. We more commonly compare 8th grade scores to those of previous 8th graders, but measuring cohort gains is also of interest.
A note of caution before proceeding it is possible to do well on the below gains analysis without ranking terribly high. Likewise you could have the highest overall 8th grade scores but also had high 4th grade scores four years earlier and look meh in this particular analysis. Like achievement gaps, each state’s gain score requires a close look before drawing conclusions- but generally speaking the states with the biggest scores below would have started with modest 4th grade scores and then shown much higher scores for the same students as 8th graders. Obviously factors other than school system effectiveness could come into play (massive gentrification in the District of Columbia comes readily to mind) and every state will have students both come and go between 2011 and 2015.
Okay now that you’ve read the warning label:
In terms of context, Arizona’s 4th graders scored 5 points below the national average in 4th grade math in 2011 but two points higher in 8th grade math in 2015. There is nothing about starting below the national average that makes it inevitable you will crush the ball in gains. Alabama for instance had 2011 4th grade math scores 9 points below the national average but then displayed 8th grade scores in 2015 that were 14 points below the national average.
Reading gains below:
Arizona’s 4th graders scored 8 points below the national average in 4th grade reading in 2011. As 8th graders in 2015 however this group of students had scores only one point below the national average- within the margin of error thus catching them up to the national average. In short, Tom Patterson nailed it- AZ looks to have had the best 2011 to 2015 period.
So this got me to thinking-what if we tracked the same cohort gains for Arizona charter school students and compared them to statewide averages? As we’ve noted before, with the largest state charter sector as a percentage of the population, Arizona has substantially more students than the entire public school system of Wyoming. The National Alliance of Public Charter Schools also compiles data about state charter sectors, so we know that the sector (like Arizona as a whole) has a majority minority student body.
Well this is what it looks like for Math:
Keep on rocking the free world! Similar story with reading:
Given the Arizona’s charter schools rank near the top in over NAEP scores, and first in overall NAEP cohort gains between 2015 and 2011, they have a great deal to celebrate- as does Arizona as a whole. Nothing in these results makes a case for complacency Arizona has only numerically exceeded one of the national averages on the four main NAEP exams, and America remains a low performing nation. Nevertheless if this is what getting an F on the Ravitch report card looks like, what can we do to get an F minus minus?