The child needs opportunities in his life not only as a member of a family but also as a member of a children's community composed of some 30 to 35 children all in one and the same phase of development and yet of various ages, i.e. from two-and-a-half years to six years. He needs to live in an environment which makes full freedom of movement possible. He needs certain forms of developmental activities with material specially and scientifically prepared to serve as the means of development. He also needs expert help of an adult specially trained for the purpose, in order to be able to conquer and enjoy freedom of choice with regard to those developmental activities.