Thursday, July 16, 2009

Dr. Solon, call your office

One of my former colleague Gary Solon's pet peeves is the equation of "not statistically different from zero" with "equals zero". Inspired by him, I've added this to my list of pet peeves as well.

This recently-released report from the National Center for Education Statistics on the black-white test score gap includes the unfortunate formulation:
In Hawaii, the 7-point difference between the average scores for Black and White students was not statistically significant, and thus there was no Black-White gap for grade 8 reading in that state in 2007.
I should note that NCES is generally very good about these things, which makes the error all the more stark.

Hat tip: Charlie Brown