Abstract
This comprehensive mixed-methods study investigated the integration and contextualization of Global Citizenship Education (GCED) using Understanding by Design (UBD) as a guiding principle within the Araling Panlipunan (AP) curriculum and instruction. Data collection involved a variety of approaches, including semi-structured interviews, focus group discussions, classroom observations, and document analysis. These methods allowed for a thorough exploration of educators' perceptions, instructional strategies, and challenges related to GCED integration. The findings of this study revealed a spectrum of GCED incorporation across different educational settings, influenced by a myriad of factors such as institutional support, teacher training initiatives, and the structure of the curriculum itself. Despite encountering challenges inherent to qualitative data collection, such as subjectivity and potential sample bias, rigorous efforts were made to mitigate these issues through triangulation of data sources and careful sampling strategies, thus enhancing the validity and reliability of the study. The integration of qualitative and quantitative methods facilitated a comprehensive understanding of GCED integration within the AP curriculum and instruction, enabling the formulation of evidence-based recommendations for curriculum development, teacher professional development, and policy implementation. These recommendations are aimed at fostering a more robust integration of GCED principles and practices, ultimately equipping students with the necessary competencies to become responsible global citizens. This research contributes valuable insights to the field of education research, informing decision-making processes and advocating for the promotion of global citizenship education within the Philippine education system.