Tracing the development of primary students' expressed sustainability conceptions through SDG-based classroom action research.

This qualitative classroom action research study traced the development of primary school students' expressed sustainability conceptions during an 8-week interdisciplinary process based on the Sustainable Development Goals (SDGs). Participants were 31 fourth-grade students (aged 9-10) in one intact classroom of a public primary school in Istanbul, Türkiye. Instruction comprised 24 class periods of 40 min across eight weekly action research cycles; the second author taught all lessons while the first author observed every session. Data comprised pre- and post-instruction conception tasks, learning artifacts, activity-specific assessment forms, audio-recorded and verbatim-transcribed dialogue, observation records, reflective journals, and field notes, analyzed through codebook thematic analysis, criterion-referenced categorization, and a matched participant-level comparison using one common six-domain codebook at both time points. Before instruction, students' responses were dominated by everyday routines, literal notions of continuity, and isolated environmental behaviors; post-instruction responses were broader and more differentiated, the mean number of domains expressed rising from 1.58 to 3.19. Environmental content rose from 10 to 30 of the 31 students and social and ethical content from 4 to 23; resource use and future-oriented outlook, absent from every initial response, appeared in 25 and 14 final responses; and everyday-routine framing, initially expressed by 23 students, appeared in none. Responses also became longer, and expressed domains grew in almost the same proportion, so domain density was essentially unchanged (19.5 vs. 18.5 domains per 100 words): the shift the data support concerns the kind of content expressed, not its density. Relational reasoning-for example, connecting drought with agricultural production, food prices and hunger-was observed in selected dialogue episodes rather than measured across the class, and development was not uniform. Classroom evidence, including misconceptions, prompted five documented instructional adaptations, four of them within lessons. Within this classroom, the post-instruction responses were broader and more multidimensional, understood here as one dimension of emerging sustainability literacy. The findings illustrate how SDG-based, dialogic, and iteratively refined teaching can accompany such broadening. Whether conceptual change of this kind contributes to longer-term nature connectedness or environmental commitment was not examined here and is identified as a direction for subsequent research.