Young children can struggle to learn difficult disciplinary content and important skills for practicing science. Problem-based learning (PBL) may be useful for addressing such difficulties, yet evidence to support its usefulness in elementary school-aged children is limited. We considered the role of a PBL unit in improving students' genetics…

This paper gives an example of how to address the challenge of designing a learning progression that describes student thinking, with the necessary specificity to align instructional opportunities and assessment tools. We describe the Conceptual Underpinnings of Evolution project and the iterative process of developing a novel learning progression…

We investigated second and third graders' capacity to understand microevolution, given a learning progression leveraging intuitions to build more adequate explanations, problematizing core ideas within scientific practices, and in-depth study of a single domain (botany or animal behavior). The intervention was implemented in both researcher-taught…