This study describes the process of defining a hypothetical learning progression (LP) for astronomy around the big idea of "Solar System formation." At the most sophisticated level, students can explain how the formation process led to the current Solar System by considering how the planets formed from the collapse of a rotating cloud of…

This article presents an empirical study on an initial learning progression of energy, a concept of central importance to the understanding of science. Learning progressions have been suggested as one vehicle to support the systematic and successful teaching of core science concepts. Ideally, a learning progression will provide teachers with a…