Penelitian ini bertujuan untuk mendeskripsikan keterlaksanaan pembelajaran, peningkatan keterampilan proses sains, dan respon siswa terhadap penerapan model discovery learning. Jenis penelitian ini yaitu deskriptif kuantitatif dengan rancangan One Group Pretest Posttest Design. Subjek penelitian yang digunakan adalah siswa kelas VIII-A dan VIII-B SMP 3 Mojokerto. Hasil penelitian menunjukkan keterlaksanaan pembelajaran di kelas VIII-A pada pertemuan pertama sebesar 3,44   dan pertemuan kedua sebesar 3,85 sedangkan di kelas VIII-B pada pertemuan pertama sebesar  3,50 dan pertemuan kedua sebesar 3,85. Hasil signifikasi dari uji normalitas kelas VIII-A secara berturut–turut 0,200 > 0,05;0,176 > 0,05 sedangkan pada kelas VIII-B secara berturut – turut 0,176 > 0,05;0,589 > 0,05 dari signifikasi Kolmogorov-Smirnov dan Shapiro-Wilk. Hasil uji t berpasangan dengan probabilitas 0,000 kurang dari 0,05 sehingga H₀ ditolak dan H₁ diterima yang artinya ada perbedaan setelah adanya perlakuan penerapan pembelajaran discovery learning.Hasil peningkatan keterampilan proses sains siswa kelas VIII-A dapat dilihat dari hasil gain score ternormalisasi bahwa sebanyak 10 siswa termasuk dalam kriteria tinggi, 17 siswa dalam kriteria sedang, dan 2 siswa yang tergolong rendah. Di kelas VIII-B sebanyak 13 siswa termasuk dalam kriteria tinggi, 16 siswa dalam kriteria sedang, dan 1 siswa yang tergolong rendah Peningkatan setiap aspek keterampilan proses sains kelas VIII-A dengan kriteria sedang pada aspek membuat rumusan masalah, membuat hipotesis, mengidentifikasi variabel, interpretasi data dan membuat kesimpulan. Sedangkan di kelas VIII-B dengan kriteria tinggi pada aspek membuat hipotesis, kriteria sedang pada aspek membuat rumusan masalah, mengidentifikasi variabel, interpretasi data dan membuat kesimpulan. Siswa memberikan respon positif terhadap penerapan model discovery learning dengan persentase dikelas VIII-A sebesar 89,6% dan di kelas VIII-B sebesar 91,6% dengan kategori sangat baik. Hasil ini menyatakan bahwa keterampilan proses sains siswa pada submateri sifat-sifat cahaya mengalami peningkatan

Kata kunci : discovery learning, keterampilan proses sains

This study aims to describe the implementation of learning, improvement of science process skills, and student responses to the application of discovery learning models. This type of research is quantitative descriptive with the design of One Group Pretest Posttest Design. The research subjects used were students of class VIII-A and VIII-B SMP 3 Mojokerto. The results showed the implementation of learning in class VIII-A at the first meeting was 3.44 and the second meeting was 3.85. In class VIII-B the first meeting was 3.50 and the second meeting was 3.85. Significance results from the normality test of class VIII-A were respectively 0.200> 0.05, 0.176> 0.05 while in class VIII-B respectively 0.176> 0.05, 0.589> 0.05 from the significance of Kolmogorov-Smirnov and Shapiro-Wilk. The results of the t test are paired with a probability of 0,000 less than 0.05 so that H0 is rejected and H1 is accepted which means there is a difference after the treatment of the application of discovery learning. The results of the improvement of science process skills of class VIII-A students can be seen from the normalized gain score results that as many as 10 students are included in the high criteria, 17 students are in the moderate criteria, and 2 students are classified as low. In class VIII-B there were 13 students included in the high criteria, 16 students in the medium criteria, and 1 student who was classified as low Increased every aspect of science process skills class VIII-A with the criteria being in formulating the problem, making a hypothesis, identifying variables, interpretation of data and making conclusions. While in class VIII-B with high criteria on the aspect of making a hypothesis, the criteria are on aspects of formulating the problem, identifying variables, interpreting data and making conclusions. Students give a positive response to the application of discovery learning models with percentages in class VIII-A of 89.6% and in class VIII-B of 91.6% with very good categories. These results state that students' science process skills in the submersion of light properties increase

Keywords: discovery learning, science process skills