This guidebook integrates basic strategies for developing a multiage-classroom design. The book begins by describing developmentally appropriate practice (DAP), which is based on a curriculum and an instructional-delivery methodology that address the physical, social, intellectual, emotional, and aesthetic needs of young students. Students are thus permitted to move through an integrated curriculum at their individual pace. Chapter 1, "The One-Room School Revisited," provides a historical look at multiage grouping as practiced during the days of the one-room schoolhouse, and compares the one-room schoolhouse with today's multiage classrooms. Chapter 2, "Planning for Multiage Instruction: The Teacher's Role," explores the multiple roles and responsibilities of teachers in multiage classrooms, providing information on curriculum planning, instructional delivery systems, classroom organization and management, student self-directed learning, and peer tutoring. The third chapter, "Inside a Multiage Classroom: The Physical Arrangement," outlines the physical arrangements required to provide an effective environment for learning in a multiage classroom, and the fourth chapter, "Guiding and Managing: The Administrator's Role," sketches the roles and responsibilities of the principal. The final chapter: "the Multiage Classroom: Questions and Comments," presents comments from teachers, principals, parents, and community members about their perceptions of multiage classrooms. (Contains 20 annotated references and 30 references.) (LMI)