<![CDATA[This study aims to develop web-based Tanjung Puting Natural Contextual Science Teaching Materials (BAPAKAT) that integrate the natural context of Tanjung Puting into Ecology and Biodiversity for Grade VII students and to test their feasibility, effectiveness, and practicality in terms of student responses and learning outcomes. This study employed the Research and Development (R&D) method with the ADDIE model. Subjects included 20 seventh-grade students at SMP Negeri 8 Arut Selatan in the limited trial and 60 students at SMP Negeri 2 Kumai in the expanded trial, along with three science teachers. The research instruments included expert validation sheets, teacher and student response questionnaires, and learning outcome tests. The assessment results from the material expert showed a score of 4.83, categorized as Very Valid, from the media expert a score of 4.8, categorized as Very Valid, and from the language expert a score of 4, categorized as Valid. This teaching material was also deemed Very Practical based on student responses, with scores ranging from >3.25 x 4.00. Based on teacher responses from all aspects of the assessment, the score is in the range of >3.25 x 4.00, which means Very Practical. The BAPAKAT teaching material is declared Effective based on the pretest and posttest scores. In the limited trial with an N-Gain value of 0.41 (Moderate Category) and the results of the expanded trial the N-Gain value is 0.56 (Moderate Category). Thus, the web-based BAPAKAT teaching material is declared valid, practical, and effective.]]>
