These proceedings are a written record of the research presented at the 42nd annual meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education (PME-NA) held in Mazatlán, Mexico, virtually beginning May 27, 2021 and in-person June 2-6, 2021. The conference was originally scheduled to take place…

This volume, a comprehensive survey and critical analysis of today's issues in mathematics education, distills research to build knowledge and capacity in the field. The compendium is a valuable new resource that provides the most comprehensive evidence about what is known about research in mathematics education. The 38 chapters present five…

Simplicity and flexibility of the full rank linear model motivated this paper which introduces researchers to the theory necessary to understand the model and apply the theory in the analysis of some standard fixed effects experimental designs. The theory and examples should help researchers use the model as an experimental tool and a model for…

Reports on a research project to use transformation geometry to give students an opportunity to work with proportions using visual models. (YDS)