Coordinating mechanistic reasoning and systems thinking in chemistry education

Mechanistic reasoning and systems thinking are widely recognized as central forms of scientific and engineering reasoning in chemistry and across STEM disciplines. However, research on their development in science courses has largely proceeded along parallel tracks, with limited attention to how their coordination can support the integration of scientific explanation, prediction, and design-oriented problem solving in classroom practice. This paper examines the epistemic relationship between mechanistic reasoning and systems thinking, arguing that these forms of reasoning are complementary but have different epistemic aims. Mechanistic reasoning supports explanations of how interactions among entities and processes produce observable effects. In contrast, systems thinking draws attention to how constraints, boundaries, feedback relationships, and system conditions shape those mechanisms. Building on existing frameworks in both traditions, I propose an instructional model that coordinates these perspectives through iterative movement between mechanistic exploration, systemic framing, and coordinated design and revision. Through this process, learners revisit shared representational