Dylan Wiliam is a world renowned researcher and educator focusing on the professional development of teachers. In 1998, Dylan Wiliam and Paul Black published their research on formative assessment with Inside The Black Box, a publication many believe began the focus on the power of formative assessment.

Dylan Wiliam is Emeritus Professor of Educational Assessment at the Institute of Education, University of London. He has served as Dean and Head of the School of Education (and later Assistant Principal) at King's College London, Senior Research Director at the Educational Testing Service in Princeton, New Jersey, and Deputy Director (Provost) of the Institute of Education, University of London. Since 2010, he has devoted most of his time to research and teaching.

Wiliam's recent work focuses on the profound impact strategic formative assessment has on student learning. He is the co-author of Inside the Black Box, a major review of the research evidence on formative assessment, as well as Embedded Formative Assessment, Embedding Formative Assessment, the Embedding Formative Assessment Professional Development Pack, and Leadership for Teacher Learning from Learning Sciences Publishing.

James Popham says this about Dylan Wiliam:

"Few academics can digest a complex array of research findings, draw coherent conclusions from that research, then describe these conclusions in a manner comprehensible to mere mortals."