National Board Certification is an honor bestowed upon teachers who submit their practice to peer scrutiny and evaluation. Each National Board Certified Teacher has demonstrated that he or she has met or exceeded the standards for the individual area of expertise developed by practicing teachers and other experts in the field of education. Content knowledge and pedagogical expertise were assessed in a rigorous performance-based portfolio submission and essay test. These teachers are truly the master teachers in the country today.

Parker Palmer, in his book, The Courage to Teach, said:

"Resources that help us teach better are available from each other—if we could get access to them. But there, of course, is the rub. Academic culture builds barriers between colleagues even higher and wider than those between us and our students. These barriers come partly from the competition that keeps us fragmented by fear. But they also come from the fact that teaching is perhaps the most privatized of all the public professions.

When we walk into our workplace, the classroom, we close the door on our colleagues. When we emerge, we rarely talk about what happened or what needs to happen next, for we have no shared experience to talk about. Then, instead of calling this the isolationism it is and trying to overcome it, we claim it as virtue called 'academic freedom': my classroom is my castle, and the sovereigns of other fiefdoms are not welcome here."

The National Board for Professional Teaching Standards, in its development of standards describing accomplished teachings and its assessment of classroom practice, has created a way for teachers and others concerned about student learning to develop, master and reflect on new approaches to working with students.

These exhibits, Opening Classroom Doors, further break down the barriers to collegial learning and show accomplished teachers in action, teaching, questioning, explaining, modeling, collaborating, and demonstrating their art at the highest level of proficiency.