Claim KY Ranks in Top 20 for Grade 8 Science Really Doesn’t Hold Up

Over at the Prichard Committee they are claiming that Kentucky ranks in the top 20 for Grade 8 Science. Their Tweet doesn’t say on what, but this is certainly based on the Grade 8 National Assessment of Educational Progress (NAEP). Let’s look at what the data really show.

First of all, this is 2020. The latest scores available from the NAEP for Grade 8 Science are for 2015 and are half a decade old now. No one knows how Kentucky currently ranks.

Also, if you only look at the overall NAEP scores for all students, you won’t get close to a complete picture about how Kentucky really performs. The reason is that our state has a very different student demographic makeup from the rest of the country. According to the NAEP Data Explorer web tool, in the 2015 NAEP Grade 8 Science Assessment, whites made up more than 4 out of 5 students in Kentucky’s public schools. That is very different from the rest of the country where whites comprised barely a majority, just 51%, of those in the NAEP.

And, this makes a difference that even the people conducting the NAEP understand. In the 2009 NAEP Science Report Card you can find this graph on Page 32. With Figure 32 the NAEP Report Card actually uses Kentucky as a prime example of how a picture of state performance can change radially once the differing demographics of the student bodies in the comparisons are considered.

In this figure, when we only look at the overall average score for all students, Kentucky scores statistically significantly above the national average. But, if we only look at scores for white students, Kentucky’s whites score statistically significantly below the national average for whites. Once you consider that Kentucky is more than 80% white in its public schools, the impact of this very different performance picture really stands out.

If you only look at overall NAEP Grade 8 Science scores for all students back in 2015, Prichard’s claim is true, IF you only look at the overall average scores.

But, as the NAEP discussion surrounding Figure 32 above from the 2009 Science Report Card hints, even in 2015 things don’t look nearly so rosy for Kentucky once you break the scores out and do an apples to apples comparison.

This table, generated with the NAEP Data Explorer, ranks Kentucky’s white students for Grade 8 Science in 2015.

As you can see, the Bluegrass State is listed pretty close to the bottom for white student NAEP Scale Scores among the 46 states that took part in Grade 8 NAEP Science in 2015. Only 2 states scored statistically significantly worse and 22 scored statistically significantly higher, which certainly knocks Kentucky out of the top 20. To reiterate, whites in Kentucky that took the NAEP still comprised over 4 out of 5 students in the state’s public schools in 2015, so these results impact a very large proportion of all students in the Bluegrass State.If we look at white NAEP performance back in the 2009 NAEP Grade 8 Science assessment, Kentucky’s white students ranked much higher – in 28th place – and only 15 states scored statistically significantly higher while 9 scored statistically significantly lower.

So, not only is Kentucky’s predominant racial group not in the top 20, but the Bluegrass State has lost significant ground compared to other states, too.

Surprisingly, though they score much lower than white students, Kentucky’s Black students did very well on the NAEP Grade 8 Science assessment compared to Black students in other states back in 2009 when Black students in 24 other states scored statistically significantly lower. By 2015, that had changed considerably. In this latest Grade 8 NAEP Science assessment, Black students in only 5 states scored statistically significantly lower than Kentucky’s Black students.

So, is Kentucky really among the top 20 for Grade 8 Science? And, with the trend of decay shown between 2009 and 2015, is it really there today, five years after the last NAEP Grade 8 Science Assessment was given?