Joanne Jacobs makes a good point about a strange write up of CA’s API index. The article also implies that Preuss school skims, that’s not exactly the case though there are requirements.
The larger point illustrated by the API (and one principal of a public school out there once quipped to Eduwonk that anything on the API below a six is just intolerable and that he could get a five “on heroin” — and his school does a lot better than a five with really challenging kids) is that different schools achieve different results with similar students. In a rational world this sort of evidence would be used to bolster the case for public education and great public schools in all communities. In today’s through the looking glass edupolitics such schools are ripped apart by an eager band of debunking researchers because we can’t tolerate any success that might call into question any of the basic operating norms or assumptions about schools today.