Development of an Instructional Manual in Electrical Installation and Maintenance for Enhancing Practical Competency in the TVL-Industrial Arts Track

This study developed and validated an instructional manual for the Electrical Installation and Maintenance (EIM) module under the Technical-Vocational Livelihood (TVL) strand of Philippine senior high schools. Guided by the ADDIE (Analysis, Design, Development, Implementation, and Evaluation) model, the manual was designed to address gaps in standardized instructional resources and to align with the Training Regulations of the Technical Education and Skills Development Authority (TESDA) for National Certificate II (NC II). A descriptive developmental mixed-methods design was employed, combining expert validation and pretest-posttest experimental procedures. A total of 90 participants were involved, including teachers, industry professionals, and Grade 11 students. Findings revealed that the experimental group using the manual achieved a substantial mean gain of 4.73 in posttest scores compared to only 1.18 in the control group, confirming statistically significant improvement in competency (p < 0.05). Expert evaluation also rated the manual “Very Good” across domains such as instructional design, technical accuracy, and usability (overall mean = 3.71). The manual thus demonstrated its effectiveness in enhancing practical skills, reinforcing schematic knowledge, and supporting certification readiness. It further contributes by offering a standardized, competency-based instructional tool that can be adapted across similar programs. The study recommends integrating digital supplements, strengthening teacher training, and expanding modules for broader application and long-term industry alignment.