Teachers' responsibility for planning the curriculum varies from one country to another. Teachers in the USA and in England and Wales, and in a number of other European countries such as Denmark, are expected to take an active role in course-planning as part of their day-to-day professional work. The teacher's task is to decide what possibilities the content offers, what conceptual learning might arise from it, what skills might be exercised, what activities the pupils should engage in. Concept-based planning is not profoundly different from content-based planning. In this case, however, the starting-point is not a body of knowledge but a concept or principle, or perhaps a group of interrelated concepts. The Schools Council project on History, Geography and Social Science for pupils proposes the following 'key concepts' for courses in this area: communication, power, values and beliefs, conflict/consensus, similarity/difference, continuity/change, causality.