After a recent spate of reports finding that National Board (NB) certified teachers do in fact contribute to greater student learning gains than non-Board certified teachers, critics of the program have hit back. Two Tennessee education professors, John E. Stone and George Cunningham, have put forward a sensible theory in one chapter of a forthcoming book. Their conclusion is that NB teachers don't come close to producing the learning gains produced by teachers who have been identified as highly effective by means of a value-added assessment. In other words, a good value-added assessment is more likely to accurately identify teachers who really pack a punch than the less accurate, more expensive process used to identify and certify National Board teachers.

In their enthusiasm, Stone and Cunningham fail to point out that value-added is still no panacea. Primarily, no one has figured out a way to assess the value of a teacher in all subjects using the data that these assessments provide. Would a system resting on test score data ever fairly establish the value of an art or high school history teacher? Secondly, the accuracy of a value-added judgment about a teacher, while better than the National Board process, shouldn't be oversold; even Tennessee's much-lauded system fails to identify the best teachers from year to year with complete accuracy. More accurate than the National Board? Yes, but hardly perfect.

The long-standing debate over the National Board has now shifted from "Are these teachers in fact more effective?"--yes, apparently, though critics say not much--to more useful policy questions such as, "How much value does a Board-certified teacher add, how much should districts be willing to pay to get them, and are there more efficient ways to get great teachers?"