<![CDATA[Self-directed learning (SDL) is a key 21st-century competency that enables students to identify learning needs, set goals, select strategies, and manage their learning process independently. However, existing SDL instruments are generally not specifically designed for physics learning supported by interactive multimedia. This study aimed to develop a valid and reliable SDL instrument tailored to STEM-R-based interactive multimedia learning environments. The study employed a research and development framework consisting of test planning, implementation, and validity and reliability evaluation. Participants were 133 physics education students from UIN Walisongo Semarang and several other universities in Indonesia. The instrument initially consisted of five dimensions: learning awareness, learning strategies, learning activities, evaluation, and interpersonal skills. Student responses were collected using a modified Likert scale. Content validity was assessed using Aiken's V coefficient, while construct validity was examined through Exploratory Factor Analysis (EFA). The results produced 13 valid items with a Cronbach's alpha coefficient of 0.851, indicating good internal consistency and reliability. EFA further refined the initial five-dimensional theoretical model into a four-factor structure, providing empirical evidence for the instrument's construct validity. Overall, the developed instrument demonstrated satisfactory validity and reliability and can be used by lecturers and researchers to assess students' self-directed learning in physics learning environments supported by interactive multimedia.]]>
