How, when and what kind of learning takes place are key questions in all educational environments. School graduates are expected to have reached a development level whereby they have, among many fundamental skills, the ability to think critically, to plan their studies and their future, and to integrate knowledge across disciplines. However, it is…

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…