Abstract :
Pendidikan dipandang sangat penting karena melalui pendidikan dapat mewujudkan SDM unggul yang memiliki kualitas untuk bersaing secara global. Untuk menjawab tantangan tersebut, peserta didik harus memiliki keterampilan berpikir tingkat tinggi (HOTS) dan mampu memahami konsep agar dapat menganalisis suatu masalah sampai mendapatkan keputusan sebagai solusi dari masalah yang ada. Kenyataannya, Observasi di SMAS Kristen Rantepao menunjukkan bahwa peserta didik kelas 10 IPA 3 memiliki HOTS dan pemahaman konsep yang rendah. Beberapa penyebab yaitu peserta didik tidak tertarik karena sulit memahami materi, proses pembelajaran masih berpusat pada guru. Model PBL (Problem Based Learning) dipilih sebagai solusi atas permasalahan tersebut. Tujuan penelitian ini yaitu untuk meningkatkan HOTS dan pemahaman konsep melalui penerapan model PBL dan mengetahui langkah-langkah penerapan model PBL yang dapat meningkatkan HOTS dan pemahaman konsep peserta didik. Metode penelitian yang digunakan adalah Penelitian Tindakan Kelas (PTK) yang terdiri dari dua siklus (perencanaan, pelaksanaan, pengamatan, dan refleksi). Penelitian ini melibatkan peserta didik kelas 10 IPA 3 SMAS Kristen Rantepao yang terdiri dari 11 laki-laki dan 21 perempuan. Instrumen penelitian yang digunakan adalah lembar observasi penerapan model PBL, lembar observasi aktivitas peserta didik, lembar soal tes, lembar angket peserta didik, lembar panduan wawancara guru pengamat dan dan peserta didik, lembar catatan lapangan guru pengamat, dan jurnal refleksi. Hasil tes menunjukkan bahwa terjadi peningkatan HOTS dan pemahaman konsep peserta didik dari siklus satu sampai siklus dua pada; indikator 1 (84-91%), indikator 2 (78-88%), indikator 3 (63-78%), indikator 4 (91%), indikator 5 (85-88%, indikator 6 (79-88%) dan indikator 7 (88-91%). Data dari instrumen tersebut memberikan kesimpulan bahwa penerapan model PBL secara sistematis dapat meningkatkan HOTS dan pemahaman konsep perubahan lingkungan bagi peserta didik kelas 10 IPA 3 di SMAS Kristen Rantepao./ Education is seen very important because through education it can create superior human resources which has quality to compete globally. To answer these challenges, students must have higher order thinking skills (HOTS) and be able to understand concepts in order to be able to analyze a problem to get a decision as a solution to an existing problem. In fact, observations at SMAS Kristen Rantepao show that students in grade 10 IPA 3 have low higher order thinking skills (HOTS) and low concept understanding. Some causes make students are not interested namely; the lesson is difficult to understand, the learning process is still teacher learning centre. The PBL (Problem Based Learning) model was chosen as a solution to these problems. The purpose of the research is to increase HOTS and to understand of concepts through the application of the PBL model and to find out the steps for implementing the PBL model that can improve HOTS and of students' understanding concepts. The research method used Classroom Action Research (CAR) which consists of two cycles (planning, implementation, observation, and reflection). The research involved students in grade 10 IPA 3 at SMA Kristen Rantepao, which consisted of 11 boys and 21 girls. The research instruments used observation sheets for the application of the PBL model namely; student observation activity sheets, test question sheets, student questionnaire sheets, teacher and student interview guide sheets, teacher observer field notes, and reflection journals.The test results showed that there was an increasing in HOTS and students' understanding concepts from cycle one to cycle two on; indicator 1 (84-91%), indicator 2 (78-88%), indicator 3 (63-78%), indicator 4 (91%), indicator 5 (85-88%, indicator 6 (79-88%) and indicator 7 (88-91%). The data from these instruments conclude that the application of the PBL model systematically can improve HOTS and understanding concepts to environmental change for students in grade 10 Science 3 at SMA Kristen Rantepao.