The effectiveness of a problem-based learning model grounded in socio-scientific issues on students’ critical thinking skills regarding environmental change
Students’ relatively low level of critical thinking skills regarding environmental change underscores the need for a learning approach that meaningfully integrates scientific concepts with real-life issues. The purpose of this study was to determine how well a Problem-Based Learning (PBL) model combined with Socio-Scientific Issues (SSI) may help students develop their critical thinking abilities with reference to environmental change. A total of 23 tenth-grade students from a private high school in the Medan Tembung subdistrict participated in this study, which used a quasi-experimental design with a one-group pretest-posttest method. The SSI-based PBL intervention involved collaborative, real-world environmental problem-solving, encompassing investigation, evidence analysis, solution presentation, and reflection. The research instrument consisted of an essay test that had passed validity and reliability tests. The N-gain test, paired-sample t-test, and effect size were used to examine the data. With an N-gain value of 86%, classified as "effective" supported by the paired-sample t-test, which showed a significant difference between pre-test and post-test scores (p < 0.001) and a Cohen's d value of 7.333, classified as a "very large" effect, the results show that students' critical thinking abilities improved across all indicators. These results show that through problem-solving exercises, evidence-based reasoning, and environmental reflection, the SSI-based PBL model effectively develops students' critical thinking abilities. However, the results of this study are still limited to a single school with a relatively small sample size and no control group; therefore, future research is recommended to use a broader sample and a stronger experimental design.