> I read that as "[All] The schools in California [in aggregate] generally score right at or just below the median for [other states' schools in aggregate] for the entire US."

That is how I intended it as, like you, I have never seen anything else.

However, the real comment I was refuting was "This is in California where the test scores are some of the worst in the nation." That statement simply isn't supported by the data.

It is certainly possible that California does have some of the worst individual districts in the nation as it definitely has pockets of incredibly poor socioeconomic areas. However, that does not define "California schools" as an aggregate any more than the fact that California has some of the highest individually performing schools in the country by virtue of demographics as well.