Joan Moss is an Associate Professor Emerita in the Department of Applied Psychology and Human Development and at the Jackman Institute of Child Study at OISE/UT. Her research has focussed on the design of developmentally-based curricula highlighting areas of mathematics that are traditionally challenging for students. Her curriculum for rational number was published by McGraw Hill as part of a US mathematics textbook series. Since 2011, Joan has been co-principal investigator of the Math for Young Children (M4YC) where her research has been focussed on the teaching and learning of spatial reasoning and geometry in early years. Joan has worked with the Robertson Program for 10 years by sharing her expertise in mathematics teaching and learning, and leading the research components of the program.