The philosophy of the open classroom approach is discussed. It is considered to be characterized by: (1) a child-centered, self-learning environment; (2) the teacher in the role of catalyst and guide; (3) a long-term commitment to exploration of new concepts and practices; (4) the needs and growth of children as the chief concern; (5) the progression of each child at his/her own rate; (6) reinforcement of open, original modes of behavior; and (7) an emotional/intellectual atmosphere encouraging exploration, experimentation and innovation. Since changes have been slow to provide open classrooms for the kindergarten-primary group, suggestions are made for converting the traditional classroom to a group of learning centers by rearrangement of furniture and supplies. Diagrams of suggested room arrangements are provided. The following suggested learning centers are described, with lists of equipment and activities for each: the domestic center, technological center, aesthetic center, environmental (science) center, mathematics center, communications (language arts) center, library corner, social learning center, perceptual-motor development center, audiovisual center. Organizational options for dividing the classroom among centers and the teacher are described. Methods of initiating the children into the open classroom approach and similar practical problems are also discussed. (KM)