seyedi nazarlo, seyed taher, Mahmoodi, Firooz, tahmasebzadeh sheikhlar, davoud, dehganzade, hossein (2024). The Effectiveness of the Curriculum Based on Understanding by Design on Academic Achievement and Problem Solving Perception of Sixth Grade Students of the Elementary School. *Journal of Instruction and Evaluation*, 16(64), 0-0. 10.30495/jinev.2024.2000480.2966