ABSTRACT
The aim of this research is to improve students’ critical thinking skills by using the discovery learning model in a temperature and heat topic. The research was conducted in two cycles. Each cycle was consisted of planning, implementation (action), observation, and reflection. The result of the first cycle is a score of 81 which consists of 50% of students with excellent score, that is 80 < × < 100, and 50% of students got a very good score, that is 66 < × < 80. Learning management got a 2.8 score, so it belongs to the “good” category. The second cycle scored 89.08 which consists of 82.35% students with excellent score, that is 80 < × < 100, and 17.65% students got very good score, that is 66 < × < 80. Learning management got a score of 3.3, so it belongs to the “very good” category. It can be concluded that discovery learning can improve students’ critical thinking ability.
