This research aims at investigating the effectiveness of Problem Based Learning with Fishbone Diagram on the students’ critical thinking skill in the Biology learning. This research adopted a quasi-experimental design notably pretest-posttest nonequivalent control group design. Population of this research included 73 students of grade X of the State Senior High School 1 of Pundong. The population was taken by using target population, and 49 students were determined as the sample by using random sampling technique. This research adopted critical thinking tests that were administered before and after the learning process took place. The instrument to measure critical thinking skill was a test consisting of 11 items. The instrument was initially validated the expert lecturer (expert judgment) to obtain its content validity and construct validity. Subsequently, empirical validity and instrument reliability were done by using Alpha Cronbach. The data of critical thinking skill were analyzed by using independent sample t-test at the significance level of (α) = 0.05. The result showed the significance value of 0.00<0.05. This study suggests that PBL with FD was effective in developing the students’ critical thinking skill.

This research aims to: (1) develop a fesible Android-based comic media of Gajah Mungkur Dam, and (2) reveal the effectiveness of the developed comic media in improving mathematical representation and critical thinking abilities on the materials of work and energy. The research subjects are senior high school students, consisting of 262 students for the empirical testing, 36 students for the limited trial, and 72 students for the field trial. This research is research and development applying the 4D model, consisting the stages of definition, design, development, and dissemination. The research instrument includes a validation sheet, evaluation sheet, questionnaire, lesson plans, comic media, and mathematical representation and critical thinking ability tests. The developed comic media contains an introduction, comic’s work and energy materials, users’ manual, instructional video, and discussion column. The data analysis used the MANOVA test. The finding shows that the developed Android-based comic media of Gajah Mungkur Dam is feasible to use with the assessment score of 3.70 or in a very good category from the validator, and score of 3.10 or in a good category from students in the limited trial. The MANOVA test result shows that there is a significant difference between the control class and experimental class. The developed comic is effective in improving mathematical representation ability in the small effect category and in improving critical thinking skill in the medium effect category.