A self‐reported instrument to measure and foster students' science connection to life with the CARE‐KNOW‐DO model and open schooling for sustainability

National governments are concerned about the disconnection of young people from science, which hampers the development of a scientifically literate society promoting sustainable development, wellbeing, equity, and a green economy. Introduced in 2015 alongside Agenda 2030, the “open schooling” approach aims at enhancing students' science connections through real‐life problem solving with families and scientists, necessitating solid evidence for scalability and sustainability. This study conceptualizes “science connection,” a term yet underexplored, as the integration of science's meaning and purpose into personal, social, and global actions informed by socioscientific thinking. It details a novel 32‐item self‐report questionnaire developed and validated from insights of 85 teachers into “science connection”‐enhanced learning. A new consensual qualitative analysis method with visual and textual snapshots enabled developing quantitative measures from the qualitative findings with rigor. The multilanguage instrument provided just‐in‐time actionable data, enhancing the immediacy and applicability of the feedback to 2082 underserved students aged 11–18 across five countries participating in open schooling activities using the CARE‐KNOW‐DO model. This innovative feature supports open science and responsible open research, offering real‐time insights and fostering immediate educational impact. Exploratory and confirmatory factor analyses revealed five components of science connection: Confidence and aspiration in science; Fun participatory science with teachers, family, and experts; Active learning approaches; Involvement in‐and‐outside school science activities; and Valuing science's role to life‐and‐society. Many students felt connected to science— Brazil: 80%, Spain: 79%, Romania: 73%, Greece: 70%, UK: 57%— with boys: 75%, girls: 73%, nonbinary students: 56%. These differences need in‐depth research. Results suggest that science connections decline from the primary to secondary education, but the CARE‐KNOW‐DO model may reengage older students. A robust science connection enhances scientific literacy and builds science capital. This instrument aids policymakers, educators, and learners in identifying factors that facilitate or impede students' engagement with science for sustainable development efforts.