What is a spiral curriculum?

In planning a curriculum there are many questions to be answered (Harden, 1986). Much attention has been paid to aims and objectives, the content of the curriculum, teaching methods, assessment, and educational strategies such as problem-based learning, integration and community-based learning. A relatively neglected area has been the question of the organization of the content and the overall structure of the curriculum. A traditional view of the curriculum is of a series of courses, each with its own programme and assessment.There is a growing tendency, however, to break down barriers or boundaries between courses and departments and to look at the overall aims or objectives of the curriculum. It is in this context that the concept of a spiral curriculum has particular relevance.