The three key conclusions from this chapter are that spatial thinking can be taught; that learning to think spatially must take place within domain contexts; and that while transfer from one specific domain of knowledge to another is neither automatic nor easy, it is possible with appropriately structured programs and curricula. On the basis of these conclusions, the committee derives two educational principles: first, instruction should be infused across and throughout the curriculum; second, instruction should create skills that promote a lifelong interest in spatial thinking. These two principles lead in turn to ideals for the design of a K–12 curriculum that would promote and support spatial thinking. Chapter 5 explores the extent to which such curricula ideals are met by current standards-based curricula in sciences and mathematics.