the effectiveness of understanding by design pedagogical service on sixth-grade students' cognitive load

The growing complexity of instructional materials in elementary science education may impose excessive cognitive load on learners and hinder meaningful learning. therefore, identifying instructional approaches that effectively manage students' cognitive load has become an important concern in educational research. the present study investigated the effectiveness of the understanding by design (ubd) framework in reducing the cognitive load of sixth‑grade students in science. this quasi‑experimental study was conducted during the fall semester of the 2022–2023 academic year in shabestar, iran. sixty sixth‑grade students participated and were randomly assigned to an experimental group (n = 30) and a control group (n = 30). the experimental group received science instruction designed according to the ubd framework, while the control group was taught using conventional instructional methods. students' cognitive load was measured using the pass cognitive load questionnaire. the collected data were analyzed using descriptive statistics (mean and standard deviation) and inferential statistics through univariate analysis of covariance (ancova) in spss version 25. the findings indicated that ubd‑based instruction significantly reduced students' cognitive load compared with traditional teaching methods. these results suggest that aligning learning objectives, assessment evidence, and instructional activities within the ubd framework can facilitate more efficient information processing, reduce unnecessary mental effort, and ultimately enhance the quality and effectiveness of learning.