PENGEMBANGAN LEMBAR KERJA SISWA (LKS) BERORIENTASI GUIDED INQUIRY UNTUK MELATIHKAN KETERAMPILAN PROSES SAINS PADA MATERI ASAM-BASA (DEVELOPMENT OF STUDENTS WORKSHEET WITH GUIDED INQUIRY ORIENTATION TO PRACTICE SCIENCE PROCESS SKILLS IN ACID-BASE TOPIC)

Penelitian ini bertujuan mengetahui kelayakan lembar kerja siswa, melatihkan keterampilan proses sains siswa, serta hasil belajar siswa. Desain penelitian ini menggunakan model pengembangan 4-D, tetapi tahap penyebaran tidak dilakukan. Instrumen yang digunakan adalah lembar telaah, validasi, respon siswa, evaluasi keterlaksanaan guided inquiry, evaluasi keterampilan proses sains, tes keterampilan proses sains, evaluasi hasil belajar, serta pengamatan aktivitas siswa. Uji coba terbatas dilakukan terhadap 12 siswa kelas XI SMAN 16 Surabaya. Metode yang digunakan adalah angket, evaluasi, dan pengamatan. Hasil validasi menyatakan lembar kerja siswa sangat layak berdasarkan kriteria isi, bahasa, penyajian, kegrafikan, guided inquiry, dan keterampilan proses sains dengan persentase 84,63%; 89,06%; 81,25%; 84,25%; 85,42%; 78,13%. Siswa memiliki keterampilan proses sains yang mulai membudaya dengan persentase 91,66%, dan hasil belajar yang baik dengan ketuntasan 80%. Kata Kunci: lembar kerja siswa, guided inquiry, keterampilan proses sains, hasil belajar, asam-basa, kelayakan.  The aim of this study was known the feasibility of students worksheet, practice science process skills, and students’s cognitive result. This study using 4-D models, with no disseminate step. The instrument used in this study were review, validity, students’s response questionnaire, guided inquiry evaluation, science process skills evaluation, students’s cognitive evaluation, and observation of activity students sheet. Limited trial test was conducted to 12 students of 11th grade of SMAN 16 Surabaya. The method used in this study were questionnaire, evaluation, and observation. Validation result showed that students worksheet was very feasible based on criteria of content, language, presentation, graphical, guided inquiry, and science process skills as followed: 84,63%; 89,06%; 81,25%; 84,25%; 85,42%; 78,13%. Students had good developing science process skills with percentage as followed  91,66%, and good students’s cognitive result with percentage 80%. Key words: students worksheet, guided inquiry, science process skills, students’s cognitive result, acid-base, feasibility