The document discusses principles for selecting and organizing content for teaching. The first principle is to ensure content has validity, significance, balance, self-sufficiency, interest, utility and feasibility. The second principle is that while facts are important, teachers should go beyond facts by building conceptual understanding and presenting different ideas. Specific strategies mentioned include organizing around core ideas, exploring topics in depth, relating ideas to students' experiences, and promoting conceptual understanding over isolated facts. The third principle is that content should integrate cognitive, skill and affective elements including facts, concepts, thinking skills, attitudes and values.