An article in this week's Education Week (July 15) points to controversy over whether "value added" assessment of teacher effectiveness might be built on "shaky assumptions." The "Value Added" method is based on judgements as to whether individual teachers are getting greater, lesser or on par student test score gains compared with those historically predicted for their students. While significantly better than the current method of comparing the scores of this year's students with last year's different students to judge schools or teachers, serious questions remain as to whether the value added method is ready for high stakes use. Researcher Jesse Rothstein, who authored the study that was the subject of the Ed Week article, and testing expert Dan Koretz who authored the recent book Measuring Up, don't think so.
Meanwhile, it looks like the long awaited new teacher evaluation system in DCPS, developed by special assistants to the chancellor Jason Kamras and Michael Moody, relies on a "value added" assessment of individual teacher's students DC CAS scores for 55% of a teacher's professional evaluation. Stay tuned for a fair amount of controversy as this gets rolled out. DCPS isn't just planning to use this method to justify a bonus or as the basis of a pilot study as in other school districts experimenting with value added -- eg. Prince Georges County, Denver, NYC. DCPS is going right to full implementation of this untested method for as much of the teacher workforce as they have value added scores.