Book excerpt: What does ′mastery′ look like in primary science? How can teachers plan for, assess and evidence it? This book explores how ‘rich’ learning tasks that enable children to apply, analyse, evaluate, and/or create to solve exciting and novel problems support the development of mastery level knowledge and skills in primary science. - Outlines how to recognise and use assessment opportunities - Focuses on the development of conceptual understanding - Highlights and demontrates the importance of teacher questioning - Explores the theories behind ′mastery′ for primary science