<![CDATA[Problem-solving ability is a crucial competency in science learning that still requires improvement, particularly in the topic of matter and its changes. The low level of this skill highlights the need for more innovative and student-centered instructional approaches. This study aims to examine the effect of the Problem-Based Learning (PBL) model on students’ problem-solving abilities. This study aims to analyze the effect of the Problem-Based Learning (PBL) model on students’ problem-solving abilities in the topic of Matter and Its Changes at SMP Negeri 1 Silaen. The background of this research is the low level of students’ problem-solving skills due to the dominance of conventional, teacher-centered learning, which causes students to be passive and less trained in developing problem-solving strategies. This research uses a quantitative approach with a quasi-experimental design of the non-equivalent control group type. The sample was selected using purposive sampling, with Class VII-D (26 students) as the experimental group, taught using the PBL model, and Class VII-E (25 students) as the control group, taught using conventional methods. Data were collected through problem-solving ability tests in the form of essay questions administered during the pretest and posttest. The hypothesis was tested using the Independent Sample T-Test. The results showed a positive and significant effect of the Problem-Based Learning model on students’ problem-solving abilities. This is evidenced by the t-value of 4.404 at a significance level of 0.005 and a significance value of 0.000, which is smaller than 0.005; thus, H₀ is rejected. Descriptively, the average posttest score of the experimental class (77.76) is higher than that of the control class (63.76), with a mean difference of 13.437. It can be concluded that the Problem-Based Learning model is effective in improving students’ problem-solving abilities through active engagement, inquiry, and the development of critical thinking skills.]]>
