@ The Chalk Face lists a number of reasons why Value Added Measures (VAM) should not be used to evaluate educators

A fundamental premise in statistics is do not use a metric for some purpose other than the one for which it was designed. Student tests are not designed to measure teacher quality.

An ethical problem with VAM is holding one person (teacher) accountable for another person’s (student’s) performance.

Campbell’s Law.

What is tested is what is taught—the high-stakes accountability era has taught us that the more we focus on testing, the less we ask from teachers and students.

The only fair way to implement VAM is to pre- and post-test every student in every class throughout the U.S. This is not justifiable in its cost in either time or money for the outcomes.

Using VAM in any way incentivizes each teacher to use her/his students against the outcomes of other teachers’ students, possibly the most ethically damning aspect of VAM.

In Ohio, where available, VAM accounts for 50% of a teachers evaluation, even if students in their class are chronically truant.