Education Week reports on two new studies done by very well respected researchers, including Douglas Harris (who literally wrote the book on value-added measures), finding that VAM does not accurately measure teacher performance in middle and high school. They point to tracking as one of the reasons.

The find what many previous studies have found:

The scholars’ analysis also showed that teachers who taught more remedial classes tended to have lower value-added scores, on average, than those teachers who taught mainly higher-level classes.

That phenomenon was not due to the best teachers’ disproportionately teaching the more-rigorous classes, as is often asserted. Instead, the paper shows, even those teachers who taught courses at more than one level of rigor did better when their performance teaching the upper-level classes was compared against that from the lower-level classes.

I’m not ready, however, to throw my elementary school colleagues under the VAM bus. Many are studies have confirmed what these new ones have found, and have also found big problems with VAM at the elementary level.

You can read about that evidence at The Best Resources For Learning About The “Value-Added” Approach Towards Teacher Evaluation and at
 The Best Resources For Learning About Effective Student & Teacher Assessments.