River Water Quality Detection Training Using Basic Microbiology Techniques for High School Student

Abstract

This study aimed to evaluate the effectiveness of a training program on river water quality detection using basic microbiological techniques for high school students. The research employed a quasi-experimental one-group pretest–posttest design involving 50 students. The training consisted of field sampling of river water, laboratory activities including aseptic techniques, serial dilution, and bacterial culturing, as well as guided data interpretation. Data were collected using cognitive tests, a laboratory skills rubric, and student worksheets. The results showed a significant improvement in students’ conceptual understanding, with mean scores increasing from 46.25 (pretest) to 78.60 (posttest). The calculated normalized gain (N-gain) was 0.60, indicating a medium level of effectiveness. A paired sample t-test revealed a statistically significant difference between pretest and posttest scores (p < 0.001), with a very large effect size (Cohen’s d = 3.42). In addition, students demonstrated good laboratory skills, with an overall mean rubric score of 3.45 (out of 4), particularly in laboratory safety and culturing techniques. Furthermore, the training enhanced students’ scientific reasoning and environmental awareness, enabling them to interpret microbiological data and relate it to real-world water quality issues. These findings suggest that integrating hands-on microbiological practices with environmental contexts effectively improves students’ scientific literacy and practical competencies. In conclusion, the training program provides an effective and evidence-based approach for integrating microbiology and environmental education at the secondary school level, supporting both academic achievement and environmental responsibility.