Self-efficacy merupakan faktor penting dalam kemampuan pemecahan masalah matematika siswa. Kemampuan siswa dalam memecahkan masalah matematika masih sangat kurang. Salah satu faktor penyebabnya adalah self-efficacy siswa yang kurang. Tujuan dari penelitian ini, adalah 1) untuk mendeskripsikan kemampuan pemecahan masalah matematika siswa kelas VIII SMPN 3 Tarakan, 2) untuk mendeskripsikan self-efficacy siswa kelas VIII SMPN 3 Tarakan berdasarkan kategori pemecahan masalah matematika. Model penelitian yang digunakan adalah mixed methods sequential explanatory. Subjek dalam penelitian ini terdiri dari 2 siswa pada kategori tinggi, 1 siswa pada kategori sedang, dan 2 siswa pada kategori rendah. Teknik pengumpulan data menggunakan tes kemampuan pemecahan masalah matematika dan wawancara self-efficacy. Hasil penelitian menunjukkan bahwa kemampuan pemecahan masalah matematika kelas VIII SMPN 3 Kota Tarakan masih tergolong rendah. Hal tersebut ditunjukkan berdasarkan persentase hasil tes kemampuan pemecahan masalah matematika yang di dominasi oleh siswa dengan kategori kemampuan pemecahan masalah matematika yang rendah, yaitu sebesar 94,9%. Kemampuan pemecahan siswa pada kategori rendah hanya memenuhi aspek memahami masalah, namun tidak tepat dan lengkap. Banyak juga siswa kategori rendah yang tidak memberikan jawaban sama sekali, jika terdapat jawaban tertulis hanya menunjukkan bahwa siswa tidak paham dengan soal sehingga jawaban tidak berarti. Kemampuan pemecahan masalah matematika siswa pada kategori tinggi dan sedang menunjukkan bahwa subjek dapat memenuhi setiap aspek kemampuan pemecahan masalah, yakni (1) memahami masalah, (2) menganalisis masalah, (3) menyelesaikan masalah, dan (4) menarik kesimpulan. Self-efficacy siswa dengan kemampuan pemecahan masalah matematika kategori tinggi, sedang, dan rendah berbeda-beda. Siswa dengan kategori tinggi dan sedang melakukan usaha maksimal agar mampu menyelesaikan suatu masalah. Siswa kategori rendah cenderung cepat menyerah dan melakukan kecurangan ketika menemukan masalah yang sulit.

Kata Kunci: Self-Efficacy, Kemampuan Pemecahan Masalah Matematika

Students’ self-efficacy plays a key role in their capacity to tackle mathematical difficulties. Students still have very little ability for tackling mathematical issues. One of the causal factors is the lack of self-efficacy of students. The objectives of this study were to: 1) describe the mathematical problem-solving skills of eighth-graders at SMPN 3 Tarakan; and 2) describe the eighth-graders’ self-efficacy based on the category of mathematical problem-solving. Sequential explanatory mixed method research design was employed. Two students from the high category, one from the medium category, and two from the low category made up the subjects in this study. A test of math problem-solving ability and a self-efficacy interview were used to gather data. The results of the research showed that the ability to aolve mathematical problems in grade VIII of SMPN 3 Tarakan City was still relatively low. This was demonstrated by the fact that 94.9% of students in the low math problem solving ability category dominated the outcomes of math problem solving ability tests. The solving ability of students in the low category only fulfilled the aspect of understanding the problem, buat it was not precise and complete. There were also many low category students who did not give an answer at all. If there was a written answer it only showed that the students did not understand the question so the answer was meaningless. The students' mathematical problem-slving ability in the high and medium category showed that the subject could fulfill every aspect of problem-solving ability, namely (1) understand the problem, (2) analyze the problem, (3) solve the problem, and (4) draw conclusions. Self-efficacy of students with high, medium, and low math problem-solving ability was different. Students that performed well and had a high category were able to find an answer. When faced with challenging difficulties, low category students frequently gave up and/or cheated. Keyword: Self-Efficacy, Mathematical Problem Solving Ability