摘要：This study explores the effect of problem-based learning on students' lateral thinking skills in biology subjects, the concept of environmental change. This quantitative research uses a quasi-experimental model with a pre-test post-test control group design. The population in this study were students of class X MIPA Integrated High School Riyadlul Ulum academic year 2018/2019. The sample used was 2 classes consisting of 64 students taken using the cluster random sampling technique. The lateral thinking skills test includes four lateral thinking factors, namely recognizing the dominant ideas of the problem, looking for different ways of looking at things looking for different ways of looking at things, loosening rigid ways of thinking and using random ideas to generate new ideas. Test is organized in essay consisting of 20 items. Data on lateral thinking skills were obtained from the pre-test and post-test scores. Result of the research concludes that there is a significant influence of PBL model on students’ lateral thinking ability. Of the four lateral thinking factors that was studied, the factor recognizes the dominant idea of the problem became the factor whose average score is the most different between the PBL group and the non-PBL group.
