The present study was an attempt to investigate the effect of Problem-Based Learning (PBL), Predict, Observe, Explain (POE), and the combination of both (PBLPOE) on students' critical thinking skills and scientific attitudes in Biology. A pretest-posttest nonequivalent control group design was employed in this study and 132 tenth-grade students from Bengkulu, Indonesia was involved. This study was carried out from February to June 2018. An essay test was administered to assess the participants' critical thinking skills, and a checklist and an interview guideline were used to observe the students' scientific attitudes. The results of the ANCOVA analysis showed that PBL, POE, and PBLPOE had an effect on the students' critical thinking skills and scientific attitudes in Biology with p-value<0.005. The results of the LSD test indicated that PBLPOE was not significantly different from PBL, but differed considerably from POE and conventional in improving students' critical thinking. Also, LSD test on the students' scientific attitudes showed that PBLPOE differed significantly from PBL, POE, and conventional in enhancing students' scientific attitudes. The highest post-test score was observed in the PBLPOE classroom. Therefore, PBLPOE can be used to improve students' performance in Biology.

This study aimed to investigate the potential effects of problem-based learning (PBL), predict observe explain (POE), and PBLPOE on students' problem-solving skills and self-efficacy in Biology. This research is based on various facts that problem-solving skills and selfefficacy of Indonesian students in biology subjects are still low.Research Methods: This quasi-experiment employed a pretest-posttest non-equivalent control group design. One hundred and thirty-two (132) tenth graders (aged 15 to 17) from Bengkulu, Indonesia, participated in this study. The participants were homogenous concerning academic abilities. Data were collected using an essay test and observation sheets.

This study aimed to investigate the correlation between critical thinking skills and academic achievement in Biology through the implementation of problem-based learning-predict observe explain (PBLPOE) learning model. The study was conducted from February to June 2018 in the even academic year of 2017/2018. A correlational design was employed in this study. The participants consisted of tenth graders from Public Senior High School (SMAN) Number 5 in Bengkulu, Indonesia. The students’ critical thinking skills and academic achievement were measured using essay tests. The result of the regression analysis showed that there was a significant correlation between students’ critical thinking skills and academic achievement in biology, where Y=7.383 + 0.500x. The regression equation suggests that students’ academic achievement may improve as the students’ critical thinking increases. Therefore, it is advisable for the educator to promote critical thinking skills in the classroom in order to improve students’ academic achievement by, for example, implementing PBLPOE learning model.

Self-efficacy is the student's belief in the ability to perform necessary tasks or actions to achieve a particular outcome. Self-efficacy can influence students' feelings, ways of thinking, motivations, academic achievements, and social behaviors. The higher self-efficacy that students have, the higher the achievement and ability students may get. The purpose of this research was to know the self-efficacy of State Senior High School students in Bengkulu City, Indonesia toward Biology Lesson. Measurement of self-efficacy refers to 3 aspects, namely magnitude, strength, and generality. The method used was survey method. The samples of this research were 160 students of class X of academic year 2017/2018 taken from Public High School (SMAN) 1, Public High School (SMAN) 2, Public High School (SMAN) 4, Public High School (SMAN) 5 and Public High School (SMAN) 6. The results of the study showed that the average self-efficacy of students are 58.60 on magnitude aspect with the medium category, 56.85 in strength aspect with the medium category, and 48.70 in generality aspect with the low category. Based on the results of this study, it is necessary to improve the learning process especially by using models of learning that can improve students' self-efficacy in Biology Lessons.

Creative thinking is used to solve problems that cannot be solved using conventional methods. Creative thinking refers to the ability to produce new and different concepts, solutions, or ideas (Sternberg, 2003). The thought process underlying creative answers is based on the person's skills, knowledge, understanding, motivation and emotions (Ferrari et al., 2009). In psychological research, creative thinking is usually defined as a process that leads to new, original, useful, and effective products. A creative mind is characterized by its flexibility that encourages someone to imagine innovative answers to a question (Runco & Jaeger, 2012).