Tujuan penelitian ini untuk mengetahui pengaruh penerapan model pembelajaran terhadap hasil belajar biologi dan kemampuan berpikir kritis siswa. Penelitian ini dilakukan mulai bulan September 2013 di SMA Muhammadiyah Tarakan. Jenis penelitian ini adalah eksperimen semu dengan populasi siswa kelas XI IPA dan sampel sebanyak 2 kelas. Teknik pengambilan sampel menggunakan Cluster Random Sampling. Data dianalisis menggunakan software SPSS 16.0 for Window. Teknik analisis data menggunakan uji MANOVA yang dilanjutkan dengan uji Independent sample t-test. Hasil analisis pengaruh penerapan model pembelajaran Guided Inquiry terhadap hasil belajar biologi dan kemampuan berpikir kritis siswa diperoleh (F =12,37; p ttabel dan untuk kemampuan berpikir kritis siswa diperoleh thitung 3,238 pada taraf signifikansi 0,05 dan dk= 56 diperoleh nilai ttabel 1,671 berarti thitung > ttabel. Berdasarkan hasil analisis data dapat disimpulkan bahwa terdapat pengaruh penerapan model pembelajaran Guided Inquiry terhadap hasil belajar biologi dan kemampuan berpikir kritis siswa.

The purpose of this study to determine the effect of the application of the learning model against the results of biological studies and critical thinking skills of students . This study was conducted from September 2013 in SMA Muhammadiyah Tarakan This is a type of quasi-experimental study with class XI science student population and a sample of 2 classes . Sampling technique using cluster random sampling . Data were analyzed using SPSS 16.0 software for Window . Analysis using the MANOVA test followed by a test of the Independent sample t – test. Analysis of the effect of the application of the results of Guided Inquiry learning model against the results of biological studies and critical thinking skills of students obtained ( F = 12.37 , p < 0,05 ). As well as test results Independent sample t-test for Guided Inquiry learning model with the conventional model of learning biology in terms of learning outcomes obtained t arithmetic 4.210 at the 0.05 significance level and df = 56 values obtained t tabel 1,671 means t arithmetic > t table and to students' critical thinking skills obtained t rithmetic 3.238 at significance level of 0.05 and df = 56 values obtained t tabel, 1,671 means t arithmetic > t table. Based on the analysis of data it can be concluded that there are significant implementation of Guided Inquiry learning model against the results of biological studies and critical thinking skills of students.