The effect of using PBL-STEM-based worksheets on students’ critical thinking skills in Biotechnology
Critical thinking is an essential competency in science education that must be systematically developed. However, biology instruction remains predominantly teacher-centered and lacks learning resources that actively engage students in higher-order thinking. One promising approach is the use of Problem-Based Learning (PBL)-STEM-based worksheets, which integrate authentic problem-solving with interdisciplinary STEM concepts to promote meaningful and contextual learning. This research focused on assessing the effectiveness of PBL-STEM-based worksheets in enhancing students' critical thinking skills during biotechnology instruction at MAS Al-Washliyah Kedaisianam. A quasi-experimental method with a pretest-posttest control group design was employed. The sample consisted of 58 students selected through purposive sampling, with 29 students in the experimental class (X IPA-1) and 29 students in the control class (X IPA-2). Data were collected using five essay questions developed based on Ennis's critical thinking indicators. Statistical analyses included the Shapiro-Wilk normality test, Levene's test for homogeneity of variances, and the independent samples t-test using IBM SPSS Statistics version 25. The findings revealed that the experimental group's mean score increased from 50.69 on the pre-test to 72.07 on the post-test, whereas the control group's mean score improved from 50.00 to 63.28. The independent samples t-test produced a significance value of 0.008 (p < 0.05), indicating a statistically significant difference between the two groups. These results demonstrate that PBL-STEM-based worksheets significantly improve students' critical thinking skills in biotechnology. Therefore, integrating PBL and STEM through structured worksheets provides an effective instructional strategy for fostering active, inquiry-based, and critical learning in biology classrooms.