Strategy for Developing the State Catholic Religious Senior High School (SMAKN) Samosir Based on Core Values to Support Academic Achievement and Student Character Formation

The State Catholic Senior High School (SMAKN) Samosir faces a significant gap between the idealism of its Vision, Mission, and Core Values and their practical implementation, which negatively affects both student character formation and academic achievement. This Community Service Program (PkM) aims to assist the school in formulating its Core Values through a participatory approach, enhancing stakeholders' understanding of their urgency, and building technical capacity among teachers and staff for effective implementation. The Participatory Action Research (PAR) approach was applied through four phases: Diagnosis, Strategy Workshop, Practical Methodology Training, and Mentoring and Reflection. Quantitative analysis using paired t-tests revealed statistically significant improvements (t=8.47, p