Effects of guided discovery learning models on students' critical thinking ability on the materials of immune system

Critical thinking is a skill needed in the 4.0 era of education so to improve critical thinking requires the right method so that learning can develop students' critical thinking skills. The purpose of this study was to determine the effect of guided discovery learning models on students' critical thinking skills on the material of the immune system. This type of research is quasi-experimental and post-test only control group design. Samples were taken by cluster random sampling technique. A total of 69 students were made respondents divided into 2 classes, namely class XI IPA 2 (n = 35) and XI IPA 3 (n = 34). The research instrument in the form of multiple choice questions of critical thinking skills was used as a data collection tool. Data were analyzed using normality test, homogeneity test, and t test The results of this study indicate that there are significant differences between the experimental class and the control class with tcount (2,031)$mathrm{>}$ ttable (1,668). Conclusion: It can be concluded that the use of guided discovery learning models has an effect on students' critical thinking skills with the use of syntax involving students to actively think at a high level to hone their critical thinking skills.