<![CDATA[This research aimed to know the effectiveness of the cooperative type Think Talk Write in terms of studentsconceptual understanding of mathematics. The population of this research was all students of grade seventh in Junior High School 2 Seputih Mataram in academic year of 2016/2017 that were distributed into 7 classes. The samples of this research were students of VII-A and VII-D class which were chosen by purposive sampling. This research used posttest only control group design. Analysis data of the research used t-test. Based on the result of this research, it was concluded that think talk write wasnt effective in terms of studentsconceptual understanding of mathematics.Penelitian ini bertujuan untuk mengetahui efektivitas model pembelajaran kooperatif tipe think talk write ditinjau dari pemahaman konsep matematis siswa. Populasi penelitian ini adalah seluruh siswa kelas VII SMP Negeri 2 Seputih Mataram tahun pelajaran 2016/2017 yang terdistribusi dalam 7 kelas. Sampel penelitian ini adalah siswa kelas VII-A dan VII-D yang dipilih dengan teknik purposive sampling. Penelitian ini menggunakan desain posttest only control group design. Analisis data penelitian ini menggunakan uji-t. Bedasarkan hasil penelitian, diperoleh kesimpulan bahwa model pembelajaran tipe think talk write tidak efektif ditinjau dari pemahaman konsep matematis siswa.Kata kunci: efektivitas, pemahaman konsep matematis, think talk write]]>
