The Effect of the CORE (Connecting, Organizing, Reflecting, and Extending) Learning Model on Concept Mastery and Argumentation Skills of Senior High School Students in Biology

Background: In 21st-century science education, fostering both conceptual understanding and argumentation skills is essential for preparing students to engage with real-world problems critically and reflectively. However, preliminary observations in an Indonesian senior high school revealed low levels of concept mastery and weak scientific argumentation among students, particularly in biology classes. These deficits are often linked to teacher-centered approaches that limit student engagement and higher-order thinking. Aims: This study aimed to investigate the effect of the CORE (Connecting, Organizing, Reflecting, and Extending) learning model on (1) students' mastery of biological concepts, and (2) their ability to construct scientific arguments in the context of respiratory system topics. Methods: A quasi-experimental design with a pretest-posttest control group was employed involving 70 eleventh-grade students divided into experimental and control groups. The experimental group received instruction using the CORE model, while the control group followed conventional direct instruction. Data were collected using validated multiple-choice concept tests and structured observation sheets for argumentation skills. Statistical analyses included normalized gain scores (N-Gain) and independent samples t-tests. Results: The results revealed significantly higher N-Gain scores in the experimental group for both concept mastery (0.47 vs. 0.35) and argumentation skills (0.48 vs. 0.32), with p-values < 0.05. The CORE model effectively enhanced students' ability to recall, apply, and analyze biological concepts, as well as articulate claims, warrants, and rebuttals in scientific discussions. Conclusion: Integrating the CORE model into biology instruction demonstrates substantial benefits in cultivating both cognitive and argumentative competencies. This learner-centered approach encourages active engagement, deeper conceptual connections, and critical thinking. Therefore, the CORE model is recommended for broader implementation in science classrooms to improve instructional quality and student learning outcomes. The model’s structured phases not only promote understanding but also empower students to develop scientifically grounded reasoning—an essential skill in contemporary science education.