Assessment, as part of the National Curriculum, has become a contentious political issue. The new General Certificate of Education incorporates internal and continuous assessment and extended use of criterion-referencing. Government initiatives have been launched and are expected to lead to profiles and records of achievement for all school leavers within the next few years. Thios work sets out to provide a guide to the principles involved. It covers such areas as criterion referenced testing, profiles and records of achievement and self assessment.