<![CDATA[ABSTRAKMasalah utama yang mendasari penelitian ini adalah rendahnya penguasaan konsep siswa terhadap materi Tekanan Hidrostatik, yang menunjukkan adanya kebutuhan untuk memperbaiki metode pembelajaran yang ada. Tujuan penelitian ini adalah untuk mengetahui peningkatan penguasaan konsep siswa pada materi tekanan hidrostatis setelah diajarkan dengan model problem based learning di SMK Darul Wustha Jerowaru. Penelitian ini dilakukan pada semester Genap tahun pelajaran 2022/2023. Metode penelitian yang digunakan adalah mixed methods desain embedded experimental model. Subjek dalam penelitian ini berjumlah 28 siswa kelas X SMK Darul Wustha Jerowaru. Instrumen penelitian terdiri dari silabus, RPP, LKS, tes penguasaan konsep, lembar observasi keterlaksanaan pembelajaran, dan protokol wawancara. Pengumpulan data yang digunakan meliputi test, observasi, dan wawancara. Teknik analisis data kuantitatif meliputi N-Gain, uji t berpasangan, dan effect size untuk melihat besar pengaruh pembelajaran. Sementara data kualitatif dianalisis dengan data reduction, coding, data display, conclusion drawing/verivication. Hasil penelitian menunjukkan bahwa: (1) Penguasaan konsep siswa pada materi tekanan hidrostatis melalui pembelajaran model problem based learning mengalami peningkatan yang signifikan dengan N-Gain skor rata-rata sebesar 0,69 (kategori sedang), dan nilai effect size sebesar 6,2 (kategori kuat); (2) sebagian besar siswa dapat mengubah konsepsi-konsepsinya yang salah pada saat posttest. Pada materi tekanan hidrostatis sebagian besar siswa menganggap tekanan hidrostatis dipengaruhi oleh volume air dan bentuk bejana, namun pada saat postest sebagian besar siswa mampu mengubah konsepsinya menuju konsepsi yang sesuai dengan konsep tekanan hidrostatis yaitu tekanan hidrostatis dipengaruhi oleh massa jenis dan kedalaman. Kondisi ini menunjukkan bahwa model problem based learning dapat meningkatkan penguasaan konsep siswa pada materi tekanan hidrostatis. Kata Kunci: penguasaan konsep; problem based learning; tekanan hidrostatis. ABSTRACTThe main problem underlying this research is the low mastery of students' concepts in the topic of Hydrostatic Pressure, indicating a need to improve existing teaching methods. The aim of this research is to determine the improvement in students' concept mastery in the topic of hydrostatic pressure after being taught using the problem-based learning model at Darul Wustha Vocational School Jerowaru. This research was conducted in the second semester of the 2022/2023 academic year. The research method used is a mixed methods design with an embedded experimental model. The subjects in this study consisted of 28 students from class X at Darul Wustha Vocational School Jerowaru. Research instruments included syllabi, lesson plans, worksheets, concept mastery tests, learning implementation observation sheets, and interview protocols. Data collection methods included tests, observations, and interviews. Quantitative data analysis techniques included N-Gain, paired t-tests, and effect size to assess the magnitude of the learning effect. Meanwhile, qualitative data were analyzed through data reduction, coding, data display, and conclusion drawing/verification. The research results indicate that: (1) Students' mastery of the concept of hydrostatic pressure through problem-based learning showed a significant improvement, with an average N-Gain score of 0.69 (moderate category) and an effect size value of 6.2 (strong category); (2) Most students were able to correct their misconceptions during the post-test. In the topic of hydrostatic pressure, most students initially believed that hydrostatic pressure was influenced by the volume of water and the shape of the container. However, after the post-test, most students were able to adjust their concepts to align with the concept of hydrostatic pressure, which is influenced by density and depth. This condition demonstrates that the problem-based learning model can enhance students' concept mastery in the topic of hydrostatic pressure. Keywords : concept mastery; problem based learning; hydrostatic pressure]]>
