Effect of Gold Standard PBL Model on Solving Linear Equation in One Variable

This study examined the effect of the Gold Standard Project-Based Learning (GSPBL) model on Grade 8 students’ ability to solve linear equations in one variable, compared with conventional teaching, using a quasi-experimental pretest–posttest matched-group approach. The research was conducted at Mahayag National High School–Junior High School, San Miguel District, Division of Bohol, with thirty (30) Grade 8 students selected from approximately one hundred eighty (180) learners based on parental consent. A researcher-made 30-item achievement test served as both pretest and posttest, supported by a table of specifications, curriculum-based content validation, pilot testing, item analysis (difficulty and discrimination), and reliability estimation using the Kuder–Richardson formula. Group comparability was strengthened through matching procedures using pretest scores to form control and experimental groups prior to implementation. Results showed very low baseline performance, with both groups initially classified below proficiency, and both groups demonstrated statistically significant pretest-to-posttest improvement (control P-value = 0.0004; experimental P-value = 0.003). However, the posttest comparison indicated no statistically significant difference between the two groups’ performance (P-value = 0.76), suggesting comparable outcomes under the study timeframe and conditions. The study concludes that GSPBL is a viable approach for enriching students’ skills in the target competency, while recommending broader instructional support, teacher capacity-building, and future replications with longer exposure and delayed posttesting. In terms of SDGs, the study most directly aligns with SDG 4 (Quality Education) through its focus on improving mathematics learning outcomes, and it supports educational sustainability by promoting structured learner-centered instruction that can strengthen foundational problem-solving competencies in basic education.