Interesting article and new methodology on school achievement

https://www.nytimes.com/interactive/2017/12/05/upshot/a-better-way-to-compare-public-schools.html

"...But in this analysis, which measures how scores grow as student cohorts move through school, the Stanford researcher Sean Reardon argues that it’s possible to separate some of the advantages of socioeconomics from what’s actually happening in schools...."