In the midst of a controversial Los Angeles Times series linking teacher performance ito student test scores, the Economic Policy Institute has released a new briefing paper cautioning against the use of test scores–the Value-Added Model–to judge instructor performance. Authored by an all-star roster of education researchers–including Linda Darling-Hammond, Diane Ravitch, and Richard Rothstein–the paper not only lists negative effects of the model but also references studies indicating that test scores can be unreliable.Source: Atlanta Journal-Constitution