Penelitian ini bertujuan untuk mendeskripsikan faktor penghambat kolaboratif siswa dalam model pembelajaran Problem Based Learning pada mata pelajaran IPAS di kelas IV SDN 1 Cineumbeuy. Penelitian ini merupakan penelitian deskriptif kualitatif. Subjek penelitian guru wali kelas IV dan 16 orang siswa sebagai sampel penelitian, dan 8 orang siswa yang mengalami kesulitan berkolaboratif dalam pembelajaran berkelompok, 2 orang siswa yang cukup berkolaboratif, dan 6 orang siswa yang aktif berkolaboratif. Pengumpulan data dilakukan dengan wawancara, observasi, dan dokumentasi. Uji keabsahan dilakukan dengan teknik triangulasi. Data dianalisis dengan tahap reduksi data, penyajian data dan penarikan kesimpulan. Berdasarkan hasil penelitian dapat disimpulkan bahwa faktor penghambat kolaboratif siswa disebabkan oleh dua faktor yaitu fektor internal seperti 1) kurangnya keterampilan komunikasi; tidak mampunya menyampaikan pendapat dengan jelas; 2) motivasi belajar yang rendah; 3) kepribadian atau sikap siswa, sikap egois dan tidak peduli akan adanya kelompok belajar, dan eksternal yakni berasal dari lingkungan peserta didik seperti : 1) tekanan sosial atau konflik antar anggota kelompok, rasa tidak nyaman bekerja sama dengan anggota kelompok tertentu.
Kata kunci : Faktor Penghambat Kolaboratif siswa, Problem Based Learning, Mata Pelajaran IPAS

This study aims to describe the inhibiting factors of student collaboration in the Problem Based Learning, learning model in the subject of Science in grade IV of SDN 1 Cineumbeuy. This study is a qualitative descriptive study. The subjects of the study were homeroom teachers of grade IV and 16 students a research sampels, and 8 students who had difficulty collaborating in group learning, 2 students who were quite collaborative, and 6 students who were actively collaborating. Data collection was carried out by interviews, observation, and documentation. Validity testing was carried out using triangulation techniques. Data were analyzed by data reduction, data presentation and concluded that the inhibiting stages. Based on the results of the study, it can be concluded that the inhibiting factors of student collaboration are causes by two factors, namley internal factors such as 1) lack of communication skills, inability to express opinions clearly; 2) low learning motivation; 3) students personality or attitude, selfish attitude and not caring about the existence of study groups, and external factors, namley from the student environment such as: 1) social pressure of conflict between group members, discomfront in working whit certain group members.
Keywords : Inhibiting Factors in Student Collaboration, Problem-Based Learning, IPAS Subject