<![CDATA[The background of this research is a response to the low critical thinking skills of fourth-grade students in the IPAS (Natural and Social Sciences) subject. This condition is triggered by the dominance of teacher-centered teaching approaches and the suboptimal utilization of varied learning models and learning media within the educational environment. Therefore, this study aims to test the effectiveness and to comprehensively examine the impact of implementing the RADEC (Read, Answer, Discuss, Explain, Create) learning model in accelerating students' critical thinking skills in the IPAS discipline. Methodologically, this investigation adopts a quantitative approach utilizing a Quasi-Experimental Design, specifically the Nonequivalent Control Group Design. The main population consisted of all fourth-grade students in Gugus I Diponegoro, Surakarta. Through a cluster sampling procedure, SD Negeri Rejosari Surakarta was selected as the sampling location, wherein class IV B (26 students) was assigned as the experimental group and class IV A (25 students) functioned as the control group. The data collection process was conducted through tests, observations, documentation, and interviews. The evaluation measurement utilized was an essay test that had been proven valid and reliable. Furthermore, the data processing stage was executed using SPSS version 25 software, which included prerequisite testing (normality and homogeneity) and proceeded to hypothesis testing using the Independent Samples t-Test. Empirical evidence from this examination revealed a margin of 11.62 points, with the control group's average posttest score standing at 71.80, while the experimental group's score surged to 83.42. The Independent Samples t-Test calculation yielded a t-count of -12.589, accompanied by a probability value (Sig. 2-tailed) of 0.000 (< 0.05). This statistical figure validates the rejection of H₀ and the acceptance of Hₐ. Thus, it is confirmed that the application of the RADEC learning model brings a highly significant effect on improving the critical thinking skills of fourth-grade students in the IPAS subject. Practically, this learning framework has proven successful in stimulating students to become more analytical, cooperative, proactive, and innovative throughout the teaching and learning activities.]]>
