<![CDATA[The complex cultural and linguistic competencies essential for Indonesian language education highlight the need for instructional models that enhance student engagement and conceptual understanding. Conventional textbook-based instruction often fails to address these needs, particularly for at-risk learners who struggle with abstract reasoning and cultural interpretation. This study examines the effectiveness of integrating decision-aid science into game-based interactive textbooks to improve student engagement and conceptual mastery. Employing a quasi-experimental mixed-methods design, this research involved 70 high school students divided into experimental and control groups. The experimental group used an interactive digital textbook embedded with decision-oriented simulations and real-time feedback, while the control group received traditional instruction. Quantitative results show that students in the experimental group demonstrated significantly greater gains in conceptual understanding, especially among moderate- and high-risk learners (p < .001), whereas the control group exhibited negligible improvement. Qualitative findings further indicate that decision-based simulations fostered meaningful engagement, enhanced the clarity of abstract concepts, and reduced performance pressure. The novelty of this study lies in demonstrating how decision-aid science—typically applied in cognitive and behavioral research—can be operationalized within digital language learning environments to scaffold reasoning, strengthen motivation, and create low-stress learning conditions.]]>
