<![CDATA[The declining quality of science education in Indonesia, reflected by the drop in national PISA science literacy scores from 396 in 2018 to 383 in 2022, signals a persistent structural gap in instructional practice. This condition is further confirmed at the local level by three consecutive years of stagnant literacy achievement at SMP Negeri 28 Batanghari, where students consistently remain in the "moderate" competency category. A preliminary needs analysis also revealed that 57.1% of students struggled to comprehend environmental issues through conventional verbal instruction, while 90.4% believed that visual and simulation-based media would substantially enhance their understanding. This study therefore aims to develop, validate, and examine the effectiveness of interactive multimedia based on Mini Research Project (MRP) integrated with Socio-Scientific Issues (SSI) to improve science literacy and problem-solving skills among Grade IX students on the topic of Environmental Issues. The development process followed the ADDIE model (Analysis, Design, Development, Implementation, and Evaluation). Data were collected through expert validation sheets from content and media specialists, practitioner assessment instruments, student response questionnaires, a PISA-aligned science literacy test, and a problem-solving skill test constructed at cognitive levels C4–C6 based on Polya's framework. Expert validation confirmed that the developed multimedia fulfilled feasibility criteria across dimensions of curriculum alignment, conceptual accuracy, SSI contextual relevance, and technical design. Student response data from small-group and large-group trials demonstrated positive reception toward the medium's usability and interactivity. Effectiveness was measured using normalized gain (N-gain) scores derived from pre-test and post-test results. The findings suggest that integrating Mini Research Project with SSI-based interactive multimedia constitutes a pedagogically sound intervention capable of bridging the gap between theoretical science knowledge and real-world critical inquiry, offering a replicable model for enhancing 21st-century competencies in junior secondary science education.]]>
