Problem-Based Learning (PBL) Approach and Academic Performance of Students in Trigonometric Ratios

Abstract

This study investigated the effect of the Problem-Based Learning (PBL) approach on the academic performance of Grade 9 students in Trigonometric Ratios. The study involved 40 Grade 9 students enrolled during School Year 2025–2026. Specifically, it compared the pre-test and post-test performance of students taught using the Lecture Method and the PBL approach and determined whether a significant difference existed between the two instructional approaches. A true experimental research design using a pre-test–post-test control group design was employed. The control group improved from a pre-test mean of 10.35 (SD = 2.60), interpreted as Low Mastery, to a post-test mean of 27.20 (SD = 4.60), interpreted as Moving Towards Mastery. The experimental group improved from a pre-test mean of 10.00 (SD = 2.73), interpreted as Low Mastery, to a post-test mean of 34.25 (SD = 3.45), interpreted as Moving Towards Mastery. The paired-samples t-test showed a significant improvement in the experimental group, t(19) = -56.602, p < .001, with a derived Cohen’s d of approximately 12.65. The independent-samples t-test also showed a significant difference between the experimental and control groups at post-test, t(38) = -5.437, p < .001, with a derived Cohen’s d of approximately 1.72. The findings indicate that students exposed to PBL demonstrated significantly higher post-test performance than those taught using the Lecture Method, suggesting that PBL can be an effective approach for improving students’ learning outcomes in Trigonometric Ratios.