Implementation of the RADEC (Read, Answer, Discuss, Explain, and Create) Learning Model to Enhance Students' Conceptual Understanding of Buffer Solutions

Abstract

This study evaluated improvements in students’ conceptual understanding of buffer solutions through the RADEC (Read, Answer, Discuss, Explain, and Create) learning model. A quasi-experimental pretest–posttest control group design involved two eleventh-grade classes, each comprising 46 students, at SMAN 2 Tambang during the 2025/2026 academic year. The experimental class received RADEC instruction, while the control class received instruction without RADEC within a pedagogical context emphasizing deep learning. Data were collected through pretests, posttests, learning activity sheets, and observations. Analyses included normality and homogeneity tests, a one-tailed t-test, and normalized gain (N-gain) analysis. Mean scores increased from 24.17 to 83.65 in the experimental class and from 22.00 to 53.22 in the control class. The experimental class achieved a high N-gain of 0.78, whereas the control class demonstrated improvement categorized as moderate. The t-test indicated greater improvement in the experimental class (t = 10.11). Within the experimental class, the highest N-gain occurred in providing examples and nonexamples (0.93), while the lowest occurred in applying concepts or algorithms to problem solving (0.53). These findings suggest that RADEC can support conceptual understanding through structured reading, answering, discussion, explanation, and creation activities, while highlighting concept application in problem solving as an area requiring further instructional attention.