A piece of the Vergara vs. California decision, handed down by L.A. Superior Court judge Rolf Treu, is based on what appears to be completely non-existent data.
In his decision, Treu quoted Arizona State professor emeritus of education, David Berliner as having said that 1% to 3% of California teachers were "grossly ineffective." Treu then did some simple math and came up between 2,750 to 8,250 of these "grossly ineffective" teachers. There are roughly 275,00 teachers in California.
In response to a call from Jordan Weissmann of Slate on Wednesday, Berliner said:
"I pulled that out of the air.There’s no data on that. That’s just a ballpark estimate, based on my visiting lots and lots of classrooms.”
Berliner also told Weissmann that he never used the term "grossly ineffective". The 1% to 3% guesstimate attributed to Berliner came from a deposition by the plaintiffs lawyers:
"Lawyer: Dr. Berliner, over four years value-added models should be able to identify the very good teachers, right?
Berliner: They should.
Lawyer: And over four years value-added models should be able to identify the very bad teachers, right?
Berliner: They should.
Lawyer: That is because there is a small percentage of teachers who consistently have strong negative effects on student outcomes no matter what classroom and school compositions they deal with, right?
Berliner: That appears to be the case.
Lawyer: And it would be reasonable to estimate that 1 to 3 percent of teachers fall in that category, right?
The 1% to 3% figure seems to have come from the lawyers, not Berliner.
Berliner, according to Weissmann, has never encountered a teacher who is "grossly ineffective."
In a blog posting by Diane Ravitch, a Research Professor of Education at New York University, on Thursday, the pulled out of thin air data was also addressed.
Further, in a email to Weissmann, Stuart Biegel, a law professor and education expert at UCLA, stated:
“If 97 to 99 percent of California teachers are effective, you don’t take away basic, hard-won rights from everybody. You focus on strengthening the process for addressing the teachers who are not effective, through strong professional development programs, and, if necessary, a procedure that makes it easier to let go of ineffective teachers."
How this ultimately is settled is a long way off. If the out of thin air data is an indication of the strength of the plaintiffs case and the judges ruling, the appeal process should prove to be very interesting.