The purpose of this study is to examine the effect of the Problem-Based Learning (PBL) model implemented in the experimental class and to compare it with the scientific approach commonly applied in schools. This research is a quasi-experimental study with a posttest-only control group design. The population consisted of all seventh-grade students at SMP Diponegoro Depok, comprising six classes. The research sample was selected using the cluster random sampling technique, resulting in two classes: class VII.A as the experimental class applying the Problem-Based Learning model, and class VII.B as the control class applying the scientific approach. The instruments used consisted of test and non-test instruments, including a mathematical communication skills test and a mathematics belief questionnaire, both of which had passed content validity. The data analysis to examine the effect of the Problem-Based Learning model and the scientific approach employed Hotelling’s T² test and the Independent Samples T-Test. The results showed that the Problem-Based Learning (PBL) model had a significant effect on students’ mathematical communication skills and mathematics beliefs. Furthermore, PBL was superior to the scientific approach in terms of seventh-grade students’ mathematical communication skills and mathematics beliefs in the topic of statistics.
Ginting et al. (Mon,) studied this question.