Key Concepts in Educational Assessment provides expert definitions and interpretations of common terms within the policy and practice of educational assessment. Concepts such as validity, reliability, assessment of learning, assessment for learning, measurement comparability and differentiation are discussed, with broad coverage of UK and international terminology. Drawing on the expertise and experience of the authors, who have worked in a wide range of educational contexts, the entries provide: - clear definitions of the concepts - accounts of the key issues - authoritative and reliable information - suggestions for further reading. Created to support students of education on undergraduate and postgraduate courses, and established education professionals including those who are members of the Chartered Institute of Educational Assessors (CIEA), this book is an accessible guide for anyone engaged in educational assessment. The book offers the reader a clear guide to the complex field of educational assessment, and suggests routes to more detailed study. Tina Isaacs is Director of the MA in Educational Assessment at the Institute of Education, London. Catherine Zara was most recently Director of the MA in Educational Assessment and Director of the BA (Hons) in Post Compulsory Education and Training at the University of Warwick. Graham Herbert is Director of the CIEA. Steve Coombs is Head of Department for Continuing Professional Development at Bath Spa University, which offers an MA in Educational Assessment. Charles Smith is senior lecturer in economics and education at Swansea Metropolitan, University of Wales Trinity St David\\\'s.