Montessori education is an educational approach developed by Italian physician and educator Maria Montessori based on her extensive research with "phrenasthenic" or "special needs" children and characterized by an emphasis on independence, freedom within limits, and respect for a child’s natural psychological, physical, and social development. Although a range of practices exists under the name "Montessori", the Association Montessori Internationale (AMI) and the American Montessori Society (AMS) cite these elements as essential: