Abstract
Indonesian schooling faces persistent critiques for disproportionately prioritizing measurable cognitive achievement while underdeveloping holistic character formation. This study aims to develop and empirically evaluate a school-based character education model that integrates personalization and internalization mechanisms to systematically strengthen the six core dimensions of the Pancasila Student Profile (Profil Pelajar Pancasila). Utilizing a Research and Development (R&D) design adapted from Borg and Gall coupled with a quasi-experimental non-equivalent control group pretest–posttest evaluation, the model was constructed through needs analysis, expert validation, and field implementation across two distinct secondary school environments in Jakarta (N = 100) over a six-month intervention period. Data were gathered using a 57-item validated Pancasila Student Profile questionnaire () and analyzed using paired-samples and independent-samples -tests along with Cohen’s effect size metrics. The findings revealed that experimental groups receiving the personalization–internalization model demonstrated statistically significant character improvements (). The posttest mean gains exceeded the control groups by 15.26 points at SMP Labschool Jakarta (Cohen’s , very large effect) and 9.83 points at SMPN 29 Jakarta (Cohen’s , large effect), whereas control groups showed negligible change (). The study concludes that embedding character education within a structured ecosystem—synthesizing differentiated learner-centered guidance, active value internalization, intra- and extracurricular integration, and sustained school culture—effectively translates national character policy into verifiable behavioral dispositions.