<![CDATA[This study aims to determine the validity, practicality, and effectiveness of developing Problem-Based Learning (PBL)-based e-modules using Calibre to improve student learning outcomes at SMKN 1 Udanawu. This study employs the Research & Development (R&D) model based on the ADDIE framework. The research subjects were 10th-grade Marketing 5 students at SMKN 1 Udanawu. Data collection techniques included observation, questionnaires, and tests in the form of pre-tests and post-tests. The results showed that the e-module achieved a media expert validity of 93.33% and a content expert validity of 92.17%, while the practicality of the e-module was rated at 90% by teachers and 84.95% by students. The effectiveness of the e-module improving learning outcomes using the Wilcoxon test and N-Gain 0,38 with a moderate or effective category. Based on the validation results from media and subject matter experts, as well as assessments of practicality and effectiveness, the developed e-module product falls into the “very good” category and is effective for use in the learning process. This study provides a scientific contribution in the form of empirical evidence that the integration of PBL syntax with Calibre e-module management produces valid, practical, and effective digital instructional materials. Theoretically, these findings enrich the framework for the development of social constructivist-based instructional materials; the product provides a blueprint for e-module development that can be replicated across disciplines in alignment with the digital transformation of the Merdeka Curriculum.]]>
