Gotham Schools reports that the New York City Department of Education rolled out this year’s school report card grades by highlighting the grades’ stability between this year and last. That is, they argued that schools’ grades were roughly the same between years, which is supposed to serve as evidence of the system’s quality.
The city’s logic here is generally sound. As I’ve noted before, most schools don’t undergo drastic changes in their operations over the course of a year, and so fluctuations in grades among a large number of schools might serve as a warning sign that there’s something wrong with the measures being used. Conversely, it’s not unreasonable to expect from a high-quality rating system that, over a two-year period, some schools would get higher grades and some lower, but that most would stay put. That was the city’s argument this year.
The only problem is that this wasn’t really the case.