http://eyeoned.org/content/the-worst-eighth-grade-math-teacher-in-new-york-city_326/
An obvious case of value-added modeling (VAM) not working: A math teacher of gifted 7th and 8th graders gets ranked as the worst 8th grade teacher in New York City, despite the fact her students are already excelling on the high school-level Regents exams (100% of her students who tried them in January passed, with more than a third achieving perfect scores).