PENGEMBANGAN APLIKASI PEMBELAJARAN BERBASIS AUGMENTED REALITY INTERAKTIF PADA MATERI GELOMBANG MEKANIK UNTUK MENINGKATKAN PEMAHAMAN KONSEP BERBASIS SPASIAL PESERTA DIDIKNIM.: 22104050032Hauriyatul IlliyyinauthorMechanical waves are an abstract topic in physics that requires spatial ability to construct mental representations of the concepts being learned. However, the learning media currently used are not able to provide concrete and interactive spatial representations, resulting in suboptimal conceptual understanding among students. Therefore, this study aimed to develop an augmented reality -based learning application for mechanical waves, determine the quality of the product based on expert evaluation, and describe changes in students' spatial-based conceptual understanding after using the developed application. This study employed a Research and Development (R&D) approach using the ADDIE development model. The developed product was an augmented reality-based learning application. The research instruments consisted of validation sheets, product quality assessment sheets, and pretest and posttest questions. Product evaluation was conducted by two subject-matter experts and two media experts, while the limited trial involved 30 eleventh-grade students of MA Tahfidz El-Muna Q Bantul. The data were analyzed descriptively using validation scores, product quality assessment scores, and the N-Gain score. The results showed that the research instruments achieved a validity score of 0.90, indicating that they were valid. Expert evaluation indicated that the application obtained an average score of 3.62, which was categorized as very good. The limited trial showed that the average pretest score increased from 54 to 96 on the posttest, with an N-Gain score of 0.91 (high category). These findings indicate that the developed augmented reality-based learning application is of very good quality, is suitable for use as a learning medium, and has the potential to facilitate students' spatial-based conceptual understanding.371.33 Media Pembelajaran2026-07-08UIN SUNAN KALIJAGA YOGYAKARTA;FAKULTAS ILMU TARBIYAH DAN KEGURUANThesis