Douglas H. Clements is a Distinguished University Professor, Kennedy Endowed Chair in Early Childhood Learning, and Executive Director of the Marsico Institute for Early Learning at the University of Denver. Previously a kindergarten teacher for five years and a preschool teacher for one, he has conducted research and published widely on the learning and teaching of early mathematics and computer applications in mathematics education. His most recent interests are in creating, using, and evaluating a research-based curriculum and taking successful curricula to scale using technologies and learning trajectories. He has published over 185 refereed research studies, 30 books, 107 chapters, and 300 additional works. His latest books detail research-based learning trajectories in early mathematics education, including Learning and teaching early math: the learning trajectories approach. Dr. Clements has directed over 40 funded projects. He has served on the U.S. President's National Mathematics Advisory Panel, the Common Core State Standards Committee, the National Research Council’s Committee on Early Mathematics, the IOM/NRC Committee on Transforming the Workforce for Children Birth Through Age 8: A Unifying Foundation, and the NASEM Committee on science and engineering in preschool through elementary grades. Additional information can be found at http://du.academia.edu/DouglasClements and http://www.researchgate.net/profile/Douglas_Clements/