Penelitian ini bertujuan untuk mengetahui: 1) Pengaruh model pembelajaran Problem Based Learning terhadap hasil belajar biologi siswa. 2) Pengaruh self efficacy siswa terhadap hasil belajar biologi. 3) Interaksi antara model pembelajaran Problem Based Learning dengan self efficacy siswa terhadap hasil belajar IPA. Jenis penelitian menggunakan eksperimen semu dengan desain faktorial 2 2. Populasi dalam penelitian ini adalah seluruh kelas VIII MTs Negeri Tarakan. Pengambilan sampel dilakukan dengan teknik purposive sampling . Sampel dalam penelitian ini adalah kelas VIII-A dan VIII-B. Pengumpulan data dilakukan dengan menggunakan tes, lembar penilaian diri, lembar penilaian keterampilan, lembar observasi dan dokumentasi. Teknik analisis data menggunakan analisis deskriptif dan inferensial. Analisis deskriptif meliputi rata-rata hitung dan simpangan baku. Analisis inferensial menggunakan analisis variansi dua jalur. Berdasarkan hasil analisis, dapat disimpulkan bahwa: 1) Model pembelajaran Problem Based Learning berpengaruh terhadap hasil belajar pada aspek pengetahuan dan aspek keterampilan, tetapi tidak berpengaruh terhadap hasil belajar aspek sikap. 2) Self efficacy siswa berpengaruh terhadap hasil belajar siswa baik pada aspek pengetahuan, sikap maupun keterampilan. 3) Tidak terdapat interaksi antara model pembelajaran Problem Based Learning dan self efficacy belajar terhadap hasil belajar siswa baik pada aspek pengetahuan, sikap maupun keterampilan.

This research aims to find out: 1) The effect of learning model Problem Based Leraning on students’s IPA learning result. 2) The effect of student’s self efficacy on biology leraning result. 3) The interaction between learning models Problem Based Learning and student’s self efficacy on IPA learning result. Types of research uses quasi experiment with 2x2 factorial design. The population in ths research is all class eight in MTs. Negeri Tarakan. Taking sample is done by purposive sampling technique. Sample in this research is class VIII-A and VIII-B. Data collection is done by using a test, self-assessment sheet, sheet skills assessment, observation sheets, and documentation. Data analysis techniques using descriptive and inferential analysis. Descriptive analysis covering the arithmetic mean and standart deviation. Inferential analysis using variance analysis of two paths. Based on the result of the analysis, it can be concluded that: 1) Learning model Problem Based Learning effect on the learning result in the aspect of knowledge and skill aspect, but has no effect on learning result in attitude aspect. 2) Student’s self efficacy influence on student learning result both in the aspect of knowledge, attitudes and skills. 3) There is no intraction between learning model Problem Based Learning and leraning self efficacy to student’s leraning result both in the aspect of knowledge, attitudes and skills.