Dylan Wiliam is director of the Learning and Teaching Research Center at the Educational Testing Service (ETS). Prior to joining ETS in September, he was professor of educational assessment and assistant principal of King's College London, the fifth largest university in the United Kingdom. He also was a teacher for eight years in inner-city schools in London, a Nuffield Research Fellow at Chelsea College on the Graded Assessment in Mathematics Project, and a lecturer in mathematics education at King's College where he ran the teacher preparation program. In addition, he served as the academic coordinator of the Consortium for Assessment and Testing in Schools, which developed a variety of statutory and non-statutory assessments for the national curriculum of England and Wales. He has taught master's and doctorate level courses on educational assessment, research methods, and the use of information technology in academic research. He has published over 150 articles, book chapters, and books in mathematics education, education law, and educational assessment. His current main interest is in exploring how assessments may be used to support learning.