You’ve Been VAM-IFIED! Thoughts (& Graphs) on the NYC Teacher Data
Readers of my blog know I’m both a data geek and a skeptic of the usefulness of Value-added data specifically as a human resource management tool for schools and districts. There’s been much talk this week about the release of the New York City teacher ratings to the media, and subsequent publication of those data by various news outlets. Most of the talk about the ratings has focused on the error rates in the ratings, and reporters from each news outlet have spent a great deal of time hiding behind their supposed ultra-responsibleness of being sure to inform the public that these ratings are not absolute, that they have significant error ranges, etc. Matt Di Carlo over at Shanker Blog has already provided a very solid explanatory piece on the error ranges and how those ranges affect classification of teachers as either good or bad.
But, the imprecision – as represented by error ranges – of each teacher’s effectiveness estimate is but one small
