The Effect of Problem Based Learning on Critical Thinking Skills and Student Achievement
The purposes of this study are (1) to know the effect of Problem Based Learning on critical thinking, (2) to know the effect of Problem Based Learning on student achievement in cognitive aspects, (3) to know the relationship between critical thinking and student achievement in cognitive aspects in Environmental Pollution of 10th Grade in The 1 Bantul Senior High School. The research was quasi experimental research using a control group pretest posttest design. Sample was X IPA 5 as an experimental group while X IPA 6 as a control group. Data collection methods in this study were observation sheets, videos, photos, student's critical thinking skills data, and student's achiement data in cognitive aspect. Instruments that were used in this study were instrument to collect the implementation of PBL, intrument to collect the student's critical thinking skills and also student's achievement in cognitive aspect. Data analysis techniques were normality and homogeneity test, t test, analysis of covariance (ANACOVA) and Pearson correlation. The results show that (1) Problem Based Learning affects critical thinking, (2) Problem Based Learning affects student achievement in cognitive aspects, and (3) there was a significant relationship between critical thinking and student achievement in cognitive aspects. The higher critical thinking is, the higher student achievement especially cognitive aspects of the students.