DEVELOPMENT OF ELECTRICAL SYSTEM TRAINING KIT FOR INTERNAL COMBUSTION ENGINE VEHICLE AIR CONDITIONING FOR VOCATIONAL CERTIFICATE STUDENTS

Abstract

The objectives of this research were to: 1) develop a modular electrical system training kit for internal combustion engine vehicle air conditioning for vocational certificate students; 2) evaluate the appropriateness of the developed training kit; 3) compare student learning achievement in the automotive air conditioning course between the group taught using the modular training kit and the group taught via the conventional method; and 4) study student satisfaction with the learning process. The sample consisted of 40 third-year vocational certificate students from the Auto Mechanics Department at Phetchaburi Technical College during the first semester of the 2025 academic year, divided into an experimental group of 20 students and a control group of 20 students, obtained through cluster sampling via drawing lots. The research instruments comprised the modular electrical system training kit with four learning stations, active learning lesson plans, job sheets, a learning achievement test, and a satisfaction questionnaire. Statistics used for data analysis were percentage, mean, standard deviation, dependent samples $t$-test, independent samples $t$-test, and effect size calculation. The results revealed that the developed training kit and instructional packages possessed appropriateness at the highest level as rated by experts (Mean = 4.69, S.D. = 0.36). The training kit achieved an overall efficiency of 79.25/82.00, exceeding the pre-established 75/75 standard threshold. The experimental group obtained a post-test mean score of 16.40 (S.D. = 1.35), which was significantly higher than their pre-test mean score of 9.15 (S.D. = 1.42) at the .05 level (t = 22.48, df = 19, p < .001). Furthermore, the between-group comparison demonstrated that the post-test mean achievement score of the experimental group was significantly higher than that of the control group (Mean = 12.10, S.D. = 1.62) at the .05 level (t = 9.11, df = 38, p < .001), with a very large effect size (Cohen's d = 2.88, 95% CI [2.05, 3.71]). Overall satisfaction of the experimental group across all dimensions was at the highest level (Mean = 4.74, S.D. = 0.30). Additionally, the educational economic evaluation indicated that the kit required a low fabrication cost of only 28,500 Baht per unit, reducing equipment procurement budget costs by 76.25%, with a cost-effectiveness ratio of 196.55 Baht per score gain, and reducing absenteeism and dropout rates to 0.00%, effectively enhancing access to practical training tools and systematically optimizing budget expenditure.