Judge Rolf Treu based his entire ruling in the Vergara v. California case on numbers that were simply made up on the spot.
June 17, 2014

In episode number umpty-zillion of the ongoing "destroy the teachers' unions by any means possible" soap opera, I bring you the ridiculous sequel to last week's Vergara v. California decision.

As it turns out, the judge's righteous indignance over all of those so-called 'ineffective teachers' comes from one tiny bit of testimony from an expert. Said expert, when contacted, confirmed that his estimate of 1-3 percent of teachers being ineffective was nothing more than a number he pulled from the air.

Yes, you read that right. Here's the important part. Pay attention now. Said expert also confirms that no one anywhere has ever arrived at any kind of definition of what constitutes an 'ineffective teacher.'


Nowhere, it turns out. It’s made up. Or a “guesstimate,” as David Berliner, the expert witness Treu quoted, explained to me when I called him on Wednesday. It’s not based on any specific data, or any rigorous research about California schools in particular. “I pulled that out of the air,” says Berliner, an emeritus professor of education at Arizona State University. “There’s no data on that. That’s just a ballpark estimate, based on my visiting lots and lots of classrooms.” He also never used the words “grossly ineffective.”

The phrase appears to have been Treu’s shorthand to describe teachers whose students consistently perform poorly on standardized tests. But Berliner is a well-known critic of using student test scores—or “value-added models,” in the parlance of education experts—to measure teaching skills. In part, that’s because research suggests that teachers don’t really control much of how their pupils perform on exams; according to the American Statistical Association, they influence anywhere between 1 percent and 14 percent of the variation in students’ scores. As result, teachers often don’t deliver the same results year after year.

Still, if you look at enough data, there are always a few teachers who consistently underperform on test results. “There’s an occasional teacher who shows up really good a few years in a row,” Berliner said. “There are a few who show up really bad.” And that’s where the now-infamous statistic comes in. During a deposition, Berliner told me, the plaintiffs’ lawyers asked how many teachers deliver low test scores year after year. He didn’t have a hard number, so he said 1 percent to 3 percent, which he thought sounded suitably small. That led to the following exchange with a plaintiffs’ lawyer during cross-examination. (Berliner emailed me part of the transcript.)

Read on...

Judge Treu's conscience is all offended over a made-up number that bears no relationship to that which offends his conscience; to wit, ineffective teachers. He latched onto a number an expert pulled out of his butt to take due process away from the 99 percent or so who don't even fall into that arbitrary and capricious category.

Either Judge Treu is lazy or he planned his ruling in advance before any evidence was presented. I'm not sure which, but I'm betting his so-called conscience had nothing to do with it.

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