Designed to help today's educators apply to current problems the wisdom gained from more than five decades of experience with the core concept, this pamphlet sets forth basic underlying philosophy and useful guidelines to develop or refine core programs at any level of schooling. The introduction establishes the philosophical framework within which the position statement was developed. The rationale for core curriculum is then set forth as ten "Assumptions and Beliefs on which Core is Based." Each of these is elaborated, with specific implications for both the core program and core teacher. This is followed by "Suggestion Implementation Procedures" for developing a new core program or improving an existing one. Appendix A consists of a Self-Evaluation Guide for Core Teachers based on the rationale and implications, and enables educators to determine the extent to which their beliefs and practices conform to the core rationale. Appendix B lists services provided by the National Association for Core Curriculum, Inc. (TRS)