The Impact of English as a Medium of Instruction and Teachers’ Instructional Practices on Students’ Academic Performance at Mariano Matugas Memorial National High School

This descriptive correlational study investigated teachers' instructional strategies, categorized into three phases: planning, delivery, and assessment, alongside the use of English as a medium of instruction (EMI) by both teachers and students. The study also examined the correlation between the extent of EMI usage and students’ academic performance, measured through Grade Point Averages (GPA) in English, Mathematics, Science, Technology and Livelihood Education (TLE), and Music, Arts, Physical Education, and Health (MAPEH). Data were collected from 203 students and 10 teachers using the Questionnaire on English as a Medium of Instruction and the Instructional Survey Questionnaire. Statistical analysis involved mean, standard deviation, and Pearson Product Moment Correlation. Results indicated that teachers consistently implemented effective instructional strategies across all phases, while students generally demonstrated very satisfactory academic performance. Both teachers and students affirmed the extensive use of EMI in the research setting. A significant relationship was observed between teachers’ instructional practices and students’ academic performance, emphasizing the importance of effective teaching strategies. However, no significant correlation was found between students' academic performance and their perceptions of EMI, suggesting that other factors, such as language proficiency, may mediate the impact of EMI. The study concludes that teachers' instructional practices play a critical role in enhancing students' academic achievement, whereas EMI usage alone does not directly affect academic performance. Recommendations include prioritizing continuous professional development for teachers, revising and aligning curriculum designs, implementing robust EMI monitoring systems, promoting equity and inclusion through differentiated instruction, diversifying assessment strategies, engaging stakeholders actively, and advancing the dissemination of research and formulation of related policies.