Keterampilan berpikir kritis merupakan salah satu tuntutan keterampilan pembelajaran abad ke-21. Berpikir kritis merupakan suatu kemampuan yang memungkinkan siswa untuk menganalisis dan menyatukan informasi untuk memecahkan masalah dalam cakupan tertentu. Model pembelajaran Problem Based Learning (PBL) dapat meningkatkan keterampilan pemahaman konsep dan berpikir kritis karena siswa dihadapkan pada masalah kehidupan nyata (kontekstual) dari lingkungan seperti permasalahan mengenai pelestarian keanekaragaman hayati. Penelitian ini bertujuan untuk menghasilkan E-LKPD berbasis Problem Based Learning (PBL) pada submateri upaya pelestarian keanekaragaman hayati yang valid, praktis dan efektif untuk melatihkan keterampilan berpikir kritis. Pengembangan E-LKPD dilakukan menggunakan model 4D (define, design, develop, dan disseminate) tanpa tahap disseminate. Uji coba secara terbatas dilakukan pada 20 siswa kelas 10.9 SMA Muhammadiyah 2 Surabaya. Validitas E-LKPD diukur berdasarkan penilaian validator yaitu dosen ahli pendidikan dan ahli materi. Kepraktisan E-LKPD diukur berdasarkan pengamatan aktivitas siswa selama pembelajaran menggunakan E-LKPD serta respons siswa dan guru terhadap E-LKPD yang dikembangkan. Keefektifan E-LKPD diukur berdasarkan ketercapaian indikator keterampilan berpikir kritis siswa. Data validitas, kepraktisan dan keefektifan dianalisis secara deskriptif kuantitatif. Hasil penelitian menunjukkan validitas E-LKPD sebesar 97,25% dengan kategori sangat valid. Kepraktisan E-LKPD berdasarkan hasil observasi keterlaksanaan sebesar 95% dengan kategori sangat praktis, berdasarkan hasil  respons siswa sebesar 88,5% dengan kategori sangat baik dan respons guru sebesar 97% dengan kategori sangat baik. Hasil penelitian menunjukkan E-LKPD dinyatakan efektif dengan rata-rata nilai gain score 0,79 dengan kategori tinggi dan rata-rata ketercapaian indikator keterampilan berpikir kritis 88,13% dengan kategori sangat tuntas. Oleh karena itu, dapat disimpulkan bahwa E-LKPD berbasis Problem Based Learning (PBL) pada submateri upaya pelestarian keanekaragaman hayati yang dikembangkan valid, praktis dan efektif untuk melatihkan keterampilan berpikir kritis siswa kelas X SMA.

Critical thinking skills are one of the demands of 21 st-century learning. Critical thinking is an ability that allows students to analyze and combine information to solve problems within a certain scope. The Problem-Based Learning (PBL) model can improve conceptual understanding and critical thinking skills because students are faced with real-life contextual problems, such as those related to biodiversity conservation. This research aimed to produce an e-LKPD (Electronic Learning and Teaching Materials) based on Problem-Based Learning (PBL) for the sub-material of biodiversity conservation efforts that was valid, practical and effective for practicing critical thinking skills. The development of the e-LKPD was carried out using a 4D model (define, design, develop, and disseminate) without a dissemination stage. Limited trials were conducted with 20 students in grades 10.9 at SMA Muhammadiyah 2 Surabaya. The validity of the e-LKPD was measured based on the assessment of validators, namely education expert lecturers and material experts. The practicality of the e-LKPD was measured based on observation of student activities during learning using the e-LKPD, as well as student and teacher responses to the e-LKPD being developed. The effectiveness of the e-LKPD was measured based on the achievement of indicators of students’ critical thinking skills. Validity, practicality, and effectiveness data were analyzed quantitatively and descriptively. The research results showed that the validity of the e-LKPD was 97.25%, falling into the very valid category. The practicality of the e-LKPD was based on the results of implementation observations, which scored 95% in the very practical category, student responses to the e-LKPD were 88.5% in the very good category, while teacher responses were 97% in the very good category. The research results also showed that the e-LKPD was declared effective, with an average gain score of 0.79 in the high category and an average achievement of critical thinking skills indicators of 88.13% in the very complete category. Therefore, it can be concluded that the e-LKPD based on Problem-Based Learning (PBL) for the sub-material of biodiversity conservation efforts developed is valid, practical, and effective for training critical thinking skills for high school students in class X.