Problem-Based Learning in Human Organ System Instruction: Effects on Senior High Students’ Understanding, HOTS, and Engagement

Problem-based learning (PBL) competencies encompass the development of critical thinking and self-directed inquiry in students, particularly in the context of biological sciences. It involves exploring how students apply scientific concepts to real-world scenarios, shifting the focus from rote memorization of the human organ system to understanding the functional relationships and homeostatic balance required for animal survival. This study investigated the integration of Problem-Based Learning (PBL) in teaching the human organ system to Grade 12 Senior High School students, focusing on pedagogical strategies, student proficiency, and implementation challenges. Utilizing a Mixed-Methods Sequential Exploratory Design, the research presents an in-depth analysis of how teachers align instruction with the Most Essential Learning Competencies (MELCs). The study explored the effects of PBL on students’ conceptual understanding and engagement, specifically regarding the circulatory, respiratory, and nervous systems. The findings revealed that while PBL significantly enhances students’ higher-order thinking skills and knowledge levels, there is a notable struggle with evidence evaluation and independent research. Through thematic analysis and quantitative surveys, the study uncovered key challenges hindering the process, including Time Management Constraints (the “deadline rush”), Low Prior Knowledge, and Unequal Group Contributions. These insights led to the development of the PULSE (Problem-based Understanding of Learning the Systems of the body in Earth and Life Science) instructional guide. This guide offers a comprehensive framework following the stages of Presenting the problem, Understanding through research, Linking systems, Synthesizing evidence, and Evaluating outcomes, designed to bridge the gap between traditional instruction and active inquiry. The study concluded with actionable recommendations for science educators and school administrators, emphasizing the importance of scaffolded research prompts and modularized lesson blocks to support effective PBL implementation. This research contributes significantly to the field of science education by providing a contextualized pedagogical tool that aligns with national curricular shifts while addressing the practical barriers to inquiry-based learning.