Abstract:
This study was aimed at finding out the effectiveness of Problem-Based Learning (PBL) model to improve students’ ability in
solving paving block problems. This study applied the combination between the quantitative and qualitative method (mixed methods) in the
data collection and analysis. The quantitative method was used to analyze students’ conjecturing ability, while the qualitative method was
functioned to explore the data of the observation and interview. The subject of the quasi-experiment was junior secondary high school
students. Thus, the data were analyzed using the inferential statistical analysis. The result of t-test showed the sig (2-tailed) test of the pre test was 0.832 (p> 0.05). It indicated that it was not significant. It means there are two homogeneous classes in terms of students'
conjecturing ability. In addition, the analysis of the independent sample t-test in the post-test, the sig. (2-tailed) was 0.00 (p = <0.05). It was
significant. It indicated that the students’ achievement of two classes were different after giving treatments using the PBL model. The result
of analysis showed that students’ conjecturing ability from the experimental class was better than the control class. In other words, the
application of the PBL model was effective in enhancing students' conjecturing abilities in solving paving block problems.
