Nurul Mauludah, et al / Journal of Biology Education 8 (3) (2019) : 322-329 322 Unnes.J.Biol.Educ. 8 (3) (2019) Journal of Biology Education http://journal.unnes.ac.id/sju/index.php/ujbe The Effectiveness of the Problem Baesd Instruction Model with Videos on Critical Thinking Abilities of Senior High School 1 Mayong Students Nurul Mauludah 1 , Endah Peniati 1 , Priyantini Widiyaningrum 2 Biology Department, FMIPA, Universitas Negeri Semarang, Indonesia Info Article Abstrak History Article: Received : September 2019 Accepted : October 2019 Published : December 2019 The ability to think critically is needed in the 21st century so that students must have the ability to think critically. This study aims to analyze the problem-based instruction model with effective video to think critically and analyze the problem-based instruction model. This study used pre- experimental design with one group pretest-posttest design. The sample of this study were students of class XI MIPA 3 and XI MIPA 4 Senior High School 1 Mayong which were determined using purposive sampling technique. The results of data analysis showed that students' critical thinking skills reached 92.5% completeness. On average, every aspect of students' critical thinking skills are in critical and very critical criteria and the average conservation value of students is honest, creative and humanist in good, good and very good criteria. The average N-gain in both classes is included in the criteria of medium and high. Based on the results of the study, it can be concluded that the problem-based instruction model with effective video is applied to senior high school 1 Mayong student towards critical thinking skills and problem-based instruction models with videos can improve the critical thinking skills of senior high school 1 Mayong students. Keywords: critical thinking, problem-based instruction, video © 2019 Universitas Negeri Semarang ✉ Correspondence: Building D6 Lt.1 Jl Raya Sekaran Gunungpati Semarang E-mail: nurulmauludah95@gmail.com p-ISSN 2252-6579 e-ISSN 2540-833X