Gary Rubinstein notes that the two expert witnesses for the plaintiffs were Raj Chetty, the nation’s leading advocate for VAM (basing teacher evaluation on student test scores) and Thomas Kane, who led the Gates’ Measures of Effective Teaching study.

Chetty throws in his speculation about how much money an entire class loses by having even one “ineffective” teacher, and Kane speculates that students learn nothing when they have an ineffective teacher. Neither the judge nor the experts cared that there was no testimony showing that any of the nine plaintiffs had any ineffective teachers, not even one.

Rubinstein wonders in this post about Kane’s definition of months of learning. He thinks that even the judge found it hard to accept his extreme views and ignored some of them.