Evaluation of a systems thinking task for upper secondary chemistry students in the context of ocean acidification

Global challenges such as ocean acidification can be understood as complex systems involving interconnected causes, effects and relationships. To navigate this complexity, systems thinking (ST) is considered an essential competency that can be fostered through science education. However, empirically tested teaching materials for fostering ST in chemistry education remain scarce. We developed and evaluated a task on ocean acidification based on the ChEMIST table. The task includes subtasks on observation, explanation, modelling, prediction and reflection, including the construction and revision of causal maps on coral decline. The task was piloted with upper secondary students ( n = 10) and implemented in a main study ( n = 16) using semi-structured interviews. Responses were analysed by subtask, with focus on assessing granularity, complexity and causality of the causal maps. The findings are presented along five ChEMIST characteristics. Findings show that students demonstrated more analytical aspects of ST when identifying elements and direct causal links. More holistic aspects of ST emerged in prediction and reflection subtasks, where students connected ecological, societal and human dimensions of ocean acidification and considered future developments and their own role within the system. Implications include the need for explicit representational scaffolds and prompts that target feedback and cross-level integration.