Abstract

As demand for foundational competencies increases, educational initiatives have increasingly emphasized the development of self-directed learning (SDL) and 21st-century skills. As a maker technology, 3D printing (3DP) has the potential to support SDL development in secondary education when it integrates iterative testing and reflection; however, many school-based 3DP activities focus primarily on behavioural engagement or discrete content knowledge, often omitting the design process. This study examines whether participation in a 3DP-based design project enhances adolescents’ SDL and 21st-century competencies. It investigates how SDL skills are expressed across different cognitive phases of making and whether students with differing levels of initial SDL readiness benefit. Participants were 55 adolescent girls across grades 7–9 and 11 who engaged in six-session, researcher-led 3DP design challenges. These initial analyses demonstrate that students practiced and improved certain 21st-century and SDL skills during this process, while assuming responsibility for their learning and engaging in metacognitive evaluation. Recommendations for future iterations are discussed.