Douglas H. Clements is Distinguished University Professor, Kennedy Endowed Chair in Early Childhood Learning, and Executive Director of the Marsico Institute for Early and Literacy at the University of Denver. Widely regarded as a major scholar in early childhood mathematics education, one with equal relevance to the academy, to the classroom, and to the educational policy arena, Dr. Clements has significantly influenced research, policy, and practice both nationally and internationally. For example, a research study showed he was first in the USA and second in the world in a rating of the most influential math education researchers in the past half-century. In all social sciences combined, he is ranked #412 in the world ranking and #210 in United States. Previously a kindergarten teacher for five years and a preschool teacher for one year, Dr. Clements has conducted research and published widely in the areas of the learning and teaching of early mathematics, curriculum research and development, and computer applications in mathematics education. His most recent interests are creating, using, and evaluating research-based curricula and educational resources and taking successful curricula to scale using technologies and learning trajectories. He has published over 200 refereed research studies, 30 books , 107 chapters, and 300 additional works. His books detail research-based learning trajectories in early mathematics education: Early childhood mathematics education research: Learning trajectories for young children and a companion book, Learning and teaching early math: The learning trajectories approach (2021, Routledge). Dr. Clements has been the principal investigator of over 40 projects, including those funded by the National Science Foundation (NSF), the U.S. Dept. of Education’s Institute of Education Sciences (IES), the Office of Special Education Programs (OSEP), and the National Institutes of Health (NIH). Currently, Dr. Clements is Principal Investigator on two large-scale randomized cluster trial projects in early mathematics (IES and NSF) and three grants funding a research-and-development project to greatly expanded asset- and research-based resources to underserved children. These extend a successful project, funded by multiple grants from the Heising-Simons Foundation and the Bill and Melinda Gates Foundation, Scalable Professional Development in Early Mathematics: The Learning and Teaching with Learning Trajectories Tool, which continues to update and disseminate a professional development software application empirically developed and evaluated in previous projects. Clements has also developed valuable research-based resources in other domains, especially STEM, Science, Technology, Engineering and Mathematics, including Connect4Learning, or C4L, curriculum (www.connect4learning.com), see an NSF video here} and the OSEP-funded STEM Innovation for Inclusion in Early Education (STEMI2E2) Center, developing is developing resources to increase the inclusion of young children with disabilities in early high-quality STEM learning experiences. Dr. Clements has served on the U.S. President's National Mathematics Advisory Panel, Common Core State Standards Committee, National Research Council’s Committee on Early Mathematics, Institute of Medicine and National Research Council’s Committee on the Science of Children Birth to Age 8: Deepening and Broadening the Foundation for Success, National Academy of Sciences Committee on Enhancing Science and Engineering in Prekindergarten through Fifth Grade, and is co-author each of their reports (National Mathematics Advisory Panel, 2008), (NGA/CCSSO, 2010), (National Research Council, 2009), (Institute of Medicine (IOM) and National Research Council (NRC), 2015), (National Academies of Sciences, 2022), Dr. Clements has influenced research, standards, curricula, and teaching, nationally and internationally. Further, international research has validated and extended his learning trajectories and curricula. Additional information can be found at http://du.academia.edu/DouglasClements and http://www.researchgate.net/profile/Douglas_Clements/ Research has documented that, in the entire field of Math Education, Dr. Clements is the 1st most influential author in the USA, and the 2nd in the world in the past half century.