What Works Outdoors? A Systematic Literature Review of Nature-Based Instruction in Science Education

This systematic literature review examines methodological trends in nature-based instruction (NBI) in science education between 2021 and 2025, focusing on formal and school-linked learning settings.Based on searches in Scopus and Web of Science, 138 empirical studies were screened, with 58 meeting quality criteria using the Mixed Methods Appraisal Tool (MMAT).Most studies used qualitative or mixed-methods designs, drawing primarily on observations, field notes, and concept inventories.Analytic approaches leaned heavily on thematic and content analysis.Pedagogically, outdoor inquiry and place-based education were the most common strategies, supported by school gardens and, to a lesser extent, citizen science and TEK-informed programs.Outcomes focused mainly on affective domains (e.g., identity, interest, self-efficacy, nature connectedness) and cognitive gains (e.g., achievement, knowledge), with fewer studies addressing scientific practices or behavioural change.Most interventions occurred in nearby outdoor sites and were delivered through formal education.While the field shows strength in ecological validity and instructional design, recurring challenges include limited use of causal designs, short follow-up periods, and inconsistent implementation reporting.The review recommends building a shared measurement framework, expanding equity-focused research, and integrating AI tools responsibly to support future growth in outdoor science education.