How do teachers develop their understanding of the foundation principles of assessment, stay up to date with the latest classroom approaches and have the confidence to evaluate and question the effectiveness of new methods? This professional resource for teachers supports them to understand the what, why and how of assessment. It provides key knowledge on the types and purposes of assessment and explores key themes such as validity, reliability and fairness. It explores assessment in practice offering practical support for busy teachers and takes an in-depth look at how qualifications are designed and developed and how examinations are marked, graded and regulated.