Abstrak
This research aimed at finding out the effect of Project Based Learning toward students’ creative thinking and writing skill on exposition text at second grade of SMA N 1 Palembayan. It was conducted due to several problems related to students creative thinking and writing skill. First, students writing skill were still low. Second, teacher still used teacher centered approach in explain material. Third, the students’ writing was short and showed no creative thinking. Therefore, the researcher was interested to use Project Based Learning to improve creative thinking and writing skill for second grade students SMA N 1 Palembayan. This research was experimental research with quasi-experimental design. The population of this research was all of the second grade students of SMA N 1 Palembayan which consisted of 3 classes. The researcher used purposive sampling to determine the sample of the research. To collect the data, researcher used students writing test in pre-test and post-test. The data in this research was analyzed by SPSS 24. The results of the research indicated that the students score in post higher than the score of pre-test in experimental class. In creative thinking the mean score of pre-test class experiment was 60.90 while the mean score of post-test was 69.20. Pre-test control class with mean was 40.60 and post-test was 52.20. It means that PJBL gave contribution on students’ creative thinking. Meanwhile, in writing skill the mean score of pre-test class experiment was 57.00 and the mean score of post-test was 57.70. The mean score in pre-test control class was 40.15 and post-test was 54.00. It concluded that the mean score of pre-test and post-test class experimental was almost the same. So that PJBL not gave contribution on students’ writing skill. In addition, the calculating of the data in independent sample t-test showed that the value of sig. (2-tailed) was .000 0,05 for creative thinking and .535 >0,05 for writing skill. It means that the alternative hypothesis (Ha) was accepted for creative thinking and Ha was rejected for writing skill. So, there was significant effect of using PJBL toward students creative thinking and there was no significant effect of using PJBL toward students writing skill. Furthermore, the calculation of the data in paired sample t-test showed that the value of sig. (2-tailed) was .089 for creative thinking and .926 for writing skill. It means that the Ha was rejected and there was no difference between the students creative thinking and writing skill taught by using PJBL and the students taught conventionally. In conclusion, the use of PJBL not gave significant effect for students in improve their creative thinking and writing skill.