Here are the grade 4 scale score result for all students and then a disaggregation by race and family income:
And here are the matching grade 8 results:
Finally, the table below color-codes which differences are and are not significant.
Both the scores and the analysis of statistical significance shown in this post come from the NAEP Data Explorer.
Cindy Heine e-mailed me to ask why it isn't statistically significant that JCPS eighth grade black students not in the lunch program have a scale score 6 points higher than similar students nationwide. Basically, it's a bout the number of students sampled. The smaller the sample, the bigger the differences have to be to count as significant.
ReplyDeleteBecause more than half of Jefferson County's students are white and more than half are in the free and reduced lunch program, I'm sure that the black and not in the lunch program group is the smallest of the four groups shown.