<![CDATA[Conceptual understanding of joints in IPAS learning remains a problem because the material is abstract in nature and requires spatial visualization skills. The initial learning conditions in Grade VI at SD Negeri Muktiharjo Kidul 02 showed that students experienced difficulties in understanding the types, locations, and directions of joint movements due to teacher-centered learning and the use of less interactive two-dimensional visual media. This study aimed to improve students' conceptual understanding of joints through the implementation of Assemblr Edu 3D media. The study employed Classroom Action Research (CAR) based on the Kemmis and McTaggart model, which was conducted in two cycles, with each cycle consisting of planning, action, observation, and reflection stages. The research subjects were 26 Grade VI students. Data were collected through conceptual understanding tests and observations of learning activities and were then analyzed quantitatively and qualitatively. Conceptual understanding was measured through the indicators of interpreting, classifying, explaining, and comparing. The results showed an improvement in students' conceptual understanding. The percentage of classical mastery increased from 19.23% in the pre-action stage to 53.84% in Cycle I and 88.46% in Cycle II. In Cycle II, all conceptual understanding indicators also achieved results above the target, namely interpreting at 86%, classifying at 90%, explaining at 84%, and comparing at 88%. The implementation of Assemblr Edu also improved student activity and teacher performance to the very good category. Therefore, Assemblr Edu 3D media is effective in improving students' conceptual understanding of joints in Grade VI elementary school.]]>
