This paper examines how students make progress toward three-dimensional (3D) understanding of the patterns of evolution. Specifically, it proposes a learning progression that explains how scientific practices, crosscutting concepts, and disciplinary core ideas come together in naming and grouping, length of change over time, and the role of common…

Reported is the production of an instructional methodology harmonizing with Piagetian theory and enabling teenage students, including those initially mismatched to the task, to understand the mole, as revealed by their performances on a test of basic skills considered fundamental to that concept. (DS)