The scientific community is in accord on the dangers inherent in making high stakes decisions derived from test scores based on "growth models." An explicit warning was issued by the National Academies last Fall to Arne Duncan and anyone else interested enough to read the warning label on the growth model snake oil. We now know that 165 teachers fired today by The Witch were evaluated using the growth model scores, and it is clear that Rhee and Co. have blood on their hatchet and are ready for more. No support, no improvement plan, no warning, no professional development plan, just Bang, you're gone.
A clip from Bill Turque:
. . .Union leaders and some teachers have bitterly objected to IMPACT, which was devised in collaboration with a private consultant, Mathematica Policy Research. Although school officials convened teacher focus groups to discuss the plan, it was not subject to collective bargaining. Some teachers call it overly complex and dependent on an unreliable statistical methodology for linking test scores to individual teachers. WTU President George Parker said the program is designed to weed out teachers rather than to help them improve their practice.
"It's punishment-heavy and support-light," Parker said.
The IMPACT-generated dismissals are likely to spark a new round of debate about Rhee's treatment of teachers. D.C. Council Chairman Vincent C. Gray, who is challenging Mayor Adrian M. Fenty in the Sept. 14 Democratic primary, has made Rhee's management part of his critique of Fenty's education policy. . . .