Alternative pedagogical approaches may include different structures, as in the open classroom, different teacher-student relationships, as in the Quaker and free schools, and/or differing curricula and teaching methods, as in the Waldorf and Montessori schools.[1] Synonyms for "alternative" in this context include "non-traditional," "non-conventional" and "non-standardized". Alternative educators use terms such as "authentic", "holistic" and "progressive".[2]