Statisticians: Value Limited for Value Added
APRIL 11, 2014
Good teaching? Crunch those numbers.
Teacher evaluation has been a frequent topic in this space: Accomplished California Teachers (ACT) first coalesced as a teacher leadership group in large part to produce a report on evaluation that would feature teacher voice regarding current practices and promising reforms for California schools. I’ve also written frequently about an evaluation method that stands out as the worst popular idea out there – using value-added measurement (VAM) of student test scores as part of a teacher evaluation. The research evidence showing problems with VAM in teacher evaluation is solid, consistent, and comes from multiple fields and disciplines – most recently, statisticians (more on that in a moment). The evidence comes from companies, universities, and governmental studies. And the anecdotal evidence is rather damning as well: how many VAM train-wrecks do we need to see?
On the relevance of student learning to teacher evaluation, the ACT team that produced our evaluation report was influenced by the fact that many of us were National Board Certified Teachers. Our certification required evidence of student learning – after all, teaching without learning is merely a set of word or actions. Board certified or not, our team members all agreed that an effective teacher needs to be able to show student learning, as part of an analytical and reflective architecture of accomplished teaching. It doesn’t mean that student learning happens for every student on the same timeline, showing up on the same types of assessments, but effective teachers take all assessments and learning experiences into account in the constant effort to plan and improve good instruction.
Value-added measures have a certain intuitive appeal, because they claim the ability to predict the trajectory of student test scores, theoretically showing the “value” added by the Statisticians: Value Limited for Value Added | InterACT: