Hundreds of millions of dollars in public and private funding have been spent to develop, research, and evaluate the assessment system of the National Board for Professional Teaching Standards (NBPTS). In an effort to determine if this has been money well spent, the U.S. Congress commissioned the National Research Council (NRC) to develop a framework that could be used to evaluate advanced-level certification of teachers. The framework (2008) was first applied in an evaluation of NBPTS. Drawing on the recommendations outlined in this framework, this article expands the discussion of the complex relationship between teachers' NBC status and student outcomes by offering explanations of the contexts and logic for many of the research decisions that have been made.