<![CDATA[Education plays an important role in the development of the quality of human resources, especially in facing the demands of the 21st century which emphasize critical thinking skills. One learning model that is relevant to developing these skills is Problem Based Learning, which is implemented in IPAS learning for fourth-grade students at SD N 1 Cempaga. However, students’ experiences in participating in the learning process are still varied, such as difficulties in understanding problems, lack of active participation in group collaboration, and limitations in analyzing problems independently, so further research is needed. This study aims to explore students’ experiences in developing critical thinking skills through the Problem Based Learning model. The theories used in this study are constructivism, critical thinking, and social learning. This research used a qualitative approach with a phenomenological type. Data collection techniques included observation, interviews, documentation, and literature study, while data analysis from Miles & Huberman included data reduction, data presentation, conclusion drawing, and verification. The results of the study show that: (1) The experiences of fourth-grade students at SD N 1 Cempaga in participating in IPAS learning using the Problem Based Learning model encouraged students’ active involvement through activities of understanding problems, group discussions, and presenting their ideas in front of the class. (2) The aspects of critical thinking skills that developed included understanding problems, analyzing problems, evaluating through discussions, and drawing conclusions. (3) In the process of developing critical thinking skills, students experienced various internal and external challenges, and received support from teachers, peers, and learning facilities. ABSTRAK Pendidikan berperan penting dalam pengembangan kualitas sumber daya manusia, khususnya dalam menghadapi tuntutan abad ke-21 yang menekankan keterampilan berpikir kritis. Salah satu model pembelajaran yang relevan untuk mengembangkan keterampilan tersebut adalah Problem Based Learning yang diterapkan pada pembelajaran IPAS kelas IV SD N 1 Cempaga. Namun, pengalaman siswa dalam mengikuti pembelajaran masih beragam, seperti kesulitan memahami permasalahan, kurang aktif dalam kerja sama kelompok, serta keterbatasan dalam menganalisis masalah secara mandiri, sehingga perlu diteliti lebih lanjut. Penelitian ini bertujuan untuk mengeksplorasi pengalaman siswa dalam mengembangkan keterampilan berpikir kritis melalui model Problem Based Learning. Teori yang digunakan dalam penelitian ini adalah konstruktivisme, berpikir kritis, dan belajar sosial. Penelitian ini menggunakan pendekatan kualitatif dengan jenis fenomenologi. Teknik pengumpulan data meliputi observasi, wawancara, dokumentasi, dan studi kepustakaan, sedangkan analisis data dari Miles & Huberman meliputi reduksi data, penyajian data, penarikan simpulan dan verifikasi. Hasil penelitian menunjukkan bahwa: (1) Pengalaman siswa kelas IV SD N 1 Cempaga dalam mengikuti pembelajaran IPAS menggunakan model Problem Based Learning mendorong keterlibatan aktif siswa melalui kegiatan memahami masalah, diskusi kelompok, dan penyampaian hasil pemikiran di depan kelas. (2) Aspek-aspek keterampilan berpikir kritis yang berkembang yakni memahami masalah, menganalisis permasalahan, mengevaluasi melalui diskusi, dan menarik kesimpulan. (3) Dalam proses mengembangkan keterampilan berpikir kritis, siswa mengalami berbagai tantangan internal dan eksternal, serta memperoleh dukungan dari guru, teman sebaya, dan fasilitas pembelajaran. ]]>
