This booklet, one part of the Intermediate Science Curriculum Study (ISCS) Individualized Teacher Preparation modular program materials, is designed to serve as a resource and a guide in helping teachers understand individualized instruction, particularly as it applies to the ISCS program, so that teachers can intelligently discuss this teaching method with administrators, parents, students, and colleagues. Information concerning the rationale for individualized instruction is presented in six chapters: The ISCS Commitment, General Education in Science, ISCS Activities and Themes, Individualizing Instruction, To Change or Not, and A Self-Evaluation Check. Additional Information is provided in the form of nine Excursions: A Level I Investigation, A Level II Investigation, A Level III Investigation, Teaching and the Expanding Knowledge, Piaget's Stages and Their Relevance for Instruction, Science Content Sequence, Readability, Answers to Self-Evaluation Check, and More Questions and Answers. (PEB)