Izwar lubis, Selamat Triono , Ambiyar 2021. VALIDITY OF PRODUCT ON THE DEVELOPMENT OF COMPASS, OBSERVATION, DEMONSTRATION, EVALUATION (CODE) TRAINING MODEL . Turkish Journal of Computer and Mathematics Education (TURCOMAT). 12, 12 (Aug. 2021), 4753–4763. DOI:https://doi.org/10.17762/turcomat.v12i12.10722.