Application of the Problem-Based Learning Model to the Ability to Interpret Persuasive Messages in Advertising Texts

This study aims to determine students’ ability to interpret persuasive messages in advertisement texts without using the Problem Based Learning (PBL) model, to identify students’ ability when using the PBL model, and to examine the effectiveness of the PBL model in improving the ability to interpret persuasive messages in advertisement texts among eighth-grade students at SMP Negeri 41 Medan. This study employed a quantitative approach using a quasi-experimental design with a Posttest Control Group Design. The research sample consisted of two classes: Class VIII-2 as the experimental group and Class VIII-5 as the control group, each comprising 31 students. Data were collected through essay tests, observations, interviews, and documentation. The results showed that the experimental class achieved a mean posttest score of 84.19, while the control class obtained a mean posttest score of 45.32. Thus, there was a mean difference of 38.87 points, equivalent to an increase of 85.77%. These findings indicate that students who learned through the Problem Based Learning (PBL) model demonstrated higher abilities in interpreting persuasive messages in advertisement texts than those who learned through conventional teaching methods. The results of the t-test revealed that the calculated t-value (tcount = -12.744) was greater than the t-table value (ttable = 1.670), with a significance value of 0.000 < 0.05. This means that Ho was rejected and Hi was accepted. Therefore, it can be concluded that the Problem Based Learning (PBL) model is effective in improving the ability to interpret persuasive messages in advertisement texts among eighth-grade students at SMP Negeri 41 Medan.