Jenis Penelitian Ini Adalah Penelitian Eksperimen Semu Yang Bertujuan Untuk Mengetahui Pengaruh Penerapan Model Koperatif Tipe Group Investigation (GI) Terhadap Kemampuan Berpikir Kritis Siswa. Penelitian Ini Dilaksanakan Pada Bulan Maret Sampai Bulan April 2018 Di Kelas V SDN 028 Tarakan. Desain Penelitian Ini Adalah Pretest – Postest Control Group Design Dengan Populasi Siswa Kelas V Dan Sampel Terdiri Atas Dua Kelas Yaitu Kelas V A Sebagai Kelas Eksperimen Dan V B Sebagai Kelas Kontrol. Teknik Pengambilan Sampel Menggunakan Sampel Random Sampling.
Analisis Data Yang Digunakan Untuk Menganalisia Data Hasil Penelitian Adalah Deskriptif Uji Independent Sampet T-Test. Hasil Penelitian Menunjukkan Bahwa Kemampuan Berpikir Kritis Siswa Kelas Eksperimen Yang Diajar Menggunakan Model Pembelajaran Kooperatif Tipe Grup Investigation (GI) Lebih Besar Dari Pada Kemampuan Berpikir Kritis Di Kelas Kontrol Yang Diajar Menggunakan Model Konvensional. Hasil Uji Independent Sampel T-Test Terhadap Pengaruh Model Pembelajaran Kooperatif Tipe Grup Investigation (GI) Dengan Model Konvensional Ditinjau Dari Kemampuan Berpikir Kritis Siswa Diperoleh Thitung 4,243 Pada Taraf Signifikasi 0,05 Dan Df = 73 Diperoleh 1,993 Berarti Thitung>Ttabel. Dengan Demikian, Penggunaan Model Pembelajaran Kooperatif Tipe Grup Investigation (GI) Memberikan Pengaruh Yang Signifikan Terhadap Kemampuan Berpikir Kritis Siswa.

Kata Kunci: Grup Investigation (GI), Kemampuan Berpikir Kritis

This Type Of Research Was Quasi Experiment Research That Aims To Find Out The Influence Of The Application Of The Model Of The Cooperative Group Type Investigation (GI) Against The Critical Thinking Ability Of Students. This Research Was Carried Out In March And April 2018 In Class V SDN 028 Tarakan. This Was A Pretest Design Research – Posttest Control Group Design With A Student Population Of Class V And Sample Consists Of Two Classes, Namely Class V A As Experimental Class And Class V B As The Control Class. The Sampling Techniques Was Used Sample Random Sampling. To Analyze The Data The Researcher Was Used Descriptive Test Independent Sample T-Test. The Results Showed That The Ability Of Critical Thinking Students’ Experiment Class Taught By Using Cooperative Learning Model Of Group Type Investigation (GI) Is Greater Than The Control Class Who Taught By Using The Conventional Model. The Result Of Independent Sample T-Test Against The Influence Of Cooperative Learning Model Of Group Type Investigation (GI) With The Conventional Model Of Critical Thinking Ability Of Students Obtained 0,05 Significance Level At Tcalculate 4,243 And Df = 73 Retrieved 1,993 Means Tcalculate>Ttable. Thus, The Used Of Cooperative Learning Model Of Group Type Investigation (GI) Provide Significant Effects Against The Critical Thinking Ability Of Students. Keywords: Group Investigation (GI), Critical Thinking Ability