QUANTUM: Jurnal Inovasi Pendidikan Sains, Vol. 15, No. 1, 2024, 53-67 Published by Chemistry Education Study Program, Universitas Lambung Mangkurat pISSN: 2086-7328, eISSN: 2550-0716. Indexed SINTA (Rank 3), IPI, IOS, Google Scholar, MORAREF, BASE, Research Bib, SIS, TEI, ROAD and Garuda. Received : 01-03-2023, Accepted : 15-10-2023, Published : 03-04-2024 DEVELOPMENT OF MULTIMEDIA INTERACTIVE SCIENCE LEARNING BASED ON CROSS PLATFORM ON HUMAN REPRODUCTIVE SYSTEM MATERIALS IN THE NINTH GRADE OF JUNIOR HIGH SCHOOL Guntur Nurcahyanto 1 *, Irma Yuliana 2 , Nazzilah Maluha Risalam 1 , Evita Anggraini 1 , Farihatul Faizah Laela 3 1 Biology Education Study Program, Faculty of Teacher Training and Education, Universitas Muhammadiyah Surakarta Jl. Ahmad Yani, Pabelan, Kartasura, Sukoharjo 57169, Jawa Tengah, Indonesia 2 Informatics Engineering Education Study Program, Faculty of Teacher Training and Education, Universitas Muhammadiyah Surakarta Jl. Ahmad Yani, Pabelan, Kartasura, Sukoharjo 57169, Jawa Tengah, Indonesia 3 Al-Islam Junior High School 1 Surakarta Jl. Moh. Yamin No.125, Serengan, Surakarta 57154, Jawa Tengah, Indonesia *email: gn122@ums.ac.id Abstract. This study aimed to develop a multimedia interactive science learning product that is cross-platform-based (handphone and Laptop) with Articulate Storyline 3 Software. The research method used was Research and Development (R&D) with a waterfall process model from Pressman. The data analysis applied to this study consists of quantitative and qualitative data. The research results: 1). Media expert testing obtained an average value of 3.56, with a very decent category; 2). Material expert testing obtained an average value of 3.77, with a very decent category; 3) Limited Scale Test, using usability assessment on students and teachers, obtained an average system usability scale (SUS) value of 75.625, with an excellent category, so it can be concluded that interactive science learning multimedia on human reproductive system material developed is acceptable (proper) used in the process of teaching and learning activities in the ninth grade of junior high school. Keywords: multimedia interactive science, waterfall process, cross-platform INTRODUCTION The development and improvement of Information and Communication Technology (ICT) in Indonesia in the 4.0 era significantly influences the paradigm shift of learning in schools, especially in junior high schools (SMP). Information and communication technology (ICT) is essential for educational change. Especially in the learning system, ICT has changed the traditional learning system into a modern technology-based learning system, including computer media with the internet (Galang M. et al., 2016). Students of SMP Al-Islam 1 Surakarta the ninth grade consider that learning science material is difficult, especially in the Human Reproductive System material, because the material is abstract, there are too many words that need to be memorized, and many scientific terms or names are difficult to remember and understand. This resulted in a decrease in Shiva's learning outcomes in junior high school. After obtaining data on learning outcomes, grade IV human reproductive system material scores at SMP Al-Islam 1 Surakarta must be more adequate and complete because 14 students still get scores below the Minimum Completeness Criteria (KM>= 75). The percentage of students who still need to complete it is 58.33%, the average score is 67.5; the highest score is 84, and the lowest score is 40. So, based on these data, researchers feel the need to take action in learning to help teachers increase the value 53