The school system in post-Katrina New Orleans is increasingly segregated by race, class and academic performance, according to a report to be released tomorrow by the AFT, the Louisiana Federation of Teachers and United Teachers of New Orleans.

I'll leave the details until tomorrow's release, but my reading of the report is that it demonstrates two things clearly.

First, it doesn't make sense to compare achievement levels for categories of schools (state-run, charter, selective, open, etc.) when the categories don't have similar populations.  With widely varying percentages of special ed students and gifted-and-talented students, any "average" achievement level or proficiency percentage for a particular category ends up being more a measure of which kids entered the schools than what kids learned while in the schools.

Second, the difference in pre- and post-Katrina populations for individual schools makes before-and-after comparisons meaningless.  In some cases, for example, the 2007 enrollment is half the 2005 enrollment, and we have no idea whether the remaining students are disproportionately high-achieving or low-achieving.