Theoretical background materials for the development of an overall curriculum are presented in this first report for teacher use. Following descriptions concerning the middle years of schooling, current trends of curriculum objectives are discussed in connection with value systems, children's social adjustments, learning theories, and balanced arrangements. Related findings on children's thinking are analyzed for clarification of their physical and psychological developments. Curriculum contents are reviewed to show present patterns of organization in schooling. The report from the Department of Educational Research, University of Lancaster, is described as in the think-tank rather than the material-producing category. Field work is conducted through observations of qualified schools by informants, and discussions held among teachers in teachers' centers. It was concluded that each child should be challenged at a level commensurate with his abilities, and his learning activities should be directed toward further developments. Contained is a summary of opinions of 1,390 individuals, primarily elementary and secondary school teachers. Project discussion papers for local working parties, a table of working party conclusions, and a list of working parties with their report submitted are also included in appendices. Further reports are to deal with individual subjects. (CC)