<![CDATA[This quasi experimental research aimed to find out the influence of the contextual collaborative learning towards the increasing of students ability of understanding of mathematical concept. The population of this research was all students of grade VII of SMP Negeri 1 Natar in academic year of 2015/2016 which were distributed into thirteen classes. The sampling of this research was done by purposive sampling technique and it was chosen students of class VII-B and VII-D as the research sample. The design of this research was pretest-posttest control group design. The data of this research were taken by pretest and posttest in essay test. The result of hypotesis test showed that the contextual collaborative learning influences towards the increasing of ability of understanding of mathematical concept.Penelitian eksperimen semu ini bertujuan untuk mengetahui pengaruh pembelajaran kolaboratif kontekstual terhadap peningkatan kemampuan pemahaman konsep matematis siswa. Populasi penelitian ini adalah seluruh siswa kelas VII SMP Negeri 1 Natar tahun pelajaran 2015/2016 yang terdistribusi dalam tiga belas kelas. Pengambilan sampel penelitian ini menggunakan teknik purposive sampling, dan terpilih siswa kelas VII-B dan VII-D sebagai sampel. Desain penelitian ini adalah pretest-posttest control group design. Data penelitian diperoleh melalui tes awal dan tes akhir berupa soal uraian. Hasil uji hipotesis menunjukkan bahwa pembelajaran kolaboratif kontekstual berpengaruh terhadap peningkatan kemampuan pemahamanan konsep matematis.Kata kunci: kolaboratif kontekstual, konvensional, pemahaman konsep matematis]]>
