Malcolm Swan is known around the English-speaking world for the quality of the research-based materials that he and his colleagues have designed and developed, from The Language of Functions and Graphs onwards. He leads the design effort of the Shell Centre team, with particular emphasis on secondary curriculum. His research has ranged through studies on graphs, student understanding of decimals, diagnostic teaching, and student metacognition. His current work for the UK Government is on supporting high-school teachers who are embarking on a diagnostic teaching approach – helping students to learn through mistakes and misconceptions. In each project he has turned research insights into research solutions through the design and development of research-based materials.