TheNational Research Council (NRC) has combed all of the research ever done on the National Board for Professional Teaching Standards (NBPTS) and has left us with the always helpful advice that ?more research is necessary.???

That may be a slight exaggeration but not much of one. Here's the NRC takeaways on the impact and effectiveness of the National Board:

• NBPTS-certified teachers are more effective in raising student achievement than non-Board certified teachers, although the gains are small; furthermore, the evidence suggests that better teachers were inclined to pursue the credential, rather than the certification process actually improving teacher effectiveness.
• Teachers from advantaged schools and states with financial incentives were more likely to participate in the certification process, and although black teachers were equally likely to apply as white teachers, they are less likely to obtain certification.
• Board-certified teachers are more likely to remain and in the field than other teachers, and are more likely to move to assignments in high-performing schools with lower rates of poverty.
• The spillover effects on the entire educational system have been minimal, and to some extent negative: the evidence suggests that some administrators discouraged teachers with the credential from assuming leadership roles, and teachers likewise downplayed their advanced certification so as not appear to be "showing off."