Adjusting for National Trends
Ginsburg: “Crucial to Peterson’s claims is that the DC score improvement should be computed only as the excess above the national average NAEP gain….This criticism makes little sense.”
Reply: Should we adjust for national trends when assessing how well a particular district is doing over a specific period of time? In Ginsburg’s view, the nation is too heterogeneous to be commonly affected by the financial disaster of 2007 or the impact of NCLB, or some other broad, national trend. Generally speaking, trends within districts more often parallel national trends than diverge from them, and it is for that reason that the adjustment I made is routinely undertaken when estimating impacts.