Conceptual thinking helps the interdisciplinary integration of knowledge and allows the transfer of learning to occur across diverse national and international contexts. The selection and clarification of key concepts are useful to focus the curriculum and increase the depth of teaching activities. The key concepts of the international education curriculum are structured into three themes—"cultural learning", "international relations" and "global issues". Schools may focus on in-depth inquiry of a single theme or cross-theme integrated inquiry when designing the curriculum.