Effectiveness of Acid-base Modules Based on Guided Discovery Learning for Increasing Critical Thinking Skills and Learning Outcomes of Senior High School Student

The goal of this study was to reveal the level of effectiveness of acid-base modules based on Guided Discovery Learning (GDL) on Critical Thinking Skills (CTS) and student learning outcomes in chemistry learning at senior high school. Module effectiveness was determined through quasi-experimental research with a randomized control-group pretestposttest design. The sample consisted of 32 students as an experimental class and 35 students as a control class. The instrument used consisted of CTS test, pre-test and post-test. Student CTS test were analysed by percentage techniques and improvement of learning outcomes with NGain assisted SPSS software 25. The average CTS score of students found was 87.93% with very effective categories. N-Gain experimental class was 0.8 (high) that was significantly higher than that of control 0.69 (moderate). Both classes were normally distributed and homogeneous, and the t-test obtained t count > t table . The research findings show that the use of acid-base modules based on GDL can improve CTS and student learning outcomes in chemistry learning at senior high school.