Thompson: Value-Added Can't Handle The "Leo" Effect
Daniel Koretz, in Measuring Up, recounts the story of educators puzzling over a drop in test scores for a class that lasted for one year and which was repeated in subsequent years. "That's Leo," explained a teacher, referring to a particularly disruptive student that brought down performance in all of his classes. Whenever Koretz repeated that story, veteran teachers would laugh knowingly. Of course, the real problem is classes with 8 to 12 "Leos." Charter schools do not need to keep more of those students than they can handle, and the other "Leos" are dumped on the most vulnerable neighborhood schools, and then on the streets. Koretz explains why we are not able to create growth models that adequately control for the effects of concentrations of disruptive students. So, rather than trying to work around that problem when creating data-driven systems, why not provide high-quality alternative schools so that the "Leos" and their classmates can be educated?- JT (@drjohnthompson)Image via.