This book is one in a developing series of handbooks for practitioners in open and distance learning (ODL). The series covers the key roles and functions of ODL systems from the practitioner perspective. The purpose is to give practitioners advice and guidance about their tasks, functions and roles, and to enable practitioners to reflect on the critical issues they face. In this way, the series aims to model good ODL study materials and to provide key study materials for ODL training. In developing this series, the Commonwealth of Learning seeks to address the needs of ODL practitioners for accessible and practical training materials for professional development. This handbook has been developed specifically for practitioners who seek to provide primary, secondary and vocational education for out-of-school learners using ODL methods.