3 very weak arguments for using weak indicators
This post is partly in response to the Brookings Institution report released this week which urged that value-added measures be considered in teacher evaluation:
However, this post is more targeted at the punditry that has followed the Brookings report – the punditry that now latches onto this report as a significant endorsement of using value-added ratings as a major component in high-stakes personnel decisions. Personally, I didn’t read it that way. Nowhere did I see this report arguing strongly for a substantial emphasis on value-added measures. That said, I actually felt that the report based its rather modest conclusions on 3 deeply flawed arguments.
Argument 1 – Other methods of teacher evaluation are ineffective at determining good versus bad teachers because those methods are only weakly correlated with value-added measures.
Or, in other words, current value added measures, while only weak predictors of future value-added, are still