The answer is "Teachers think systematically about their practice and learn from experience".
The National Board for Professional Teaching Standards which in short is known as NBPTS was founded in 1987. And this is an impartial, charitable association in the US, devoted to advancing perfection in training and educating. NBPTS enhances instructing and learning by improving general instructor viability and perceiving and remunerating exceedingly proficient teachers who meet high and thorough guidelines.