Consistent Individual Learning Gains Following Problem-Based Learning in Automotive Lighting and Signaling Systems: A One-Group Pretest-Posttest Study in Vocational Education

Dimas Aji Pambudi; Erwin Komara Mindarta; Kurnia Elvi Futnawati; Daris Siswa Nugraha; Kusmanto Kusmanto

doi:10.70437/jedu.v4i1.129

Authors

Dimas Aji Pambudi State University of Malang
Erwin Komara Mindarta State University of Malang
Kurnia Elvi Futnawati SMK Negeri 6 Malang
Daris Siswa Nugraha SMK Negeri 6 Malang
Kusmanto Kusmanto SMK Negeri 6 Malang

DOI:

https://doi.org/10.70437/jedu.v4i1.129

Keywords:

problem-based learning, vocational education, automotive electrical systems, lighting and signaling systems, individual learning gains

Abstract

Background: Problem-Based Learning (PBL) may support technical reasoning in vocational automotive education, yet class means can obscure variation in individual response. Objective: This study examined the magnitude, robustness, and consistency of learning gains after PBL in automotive lighting and signaling systems. Methods: Pre-test and post-test scores from 23 Grade XI Light Vehicle Engineering students were analyzed using descriptive statistics, paired-samples t testing, Wilcoxon signed-rank testing, Cohen’s dz, normalized gain, correlation, and individual trajectories. Results: Mean scores increased from 36.09 (SD = 12.43) to 62.83 (SD = 15.51), with a mean gain of 26.74 points (95% CI 23.64–29.84), t(22) = 17.89, p < .001. All 23 students improved by 15–35 points; baseline rank remained strongly associated with post-test performance (r = .891, p < .001). Conclusion: PBL was associated with large, class-wide gains, although causal attribution is limited by the one-group design.