Problem-based learning (PBL) is a method of learning and teaching that allows students to focus on how and what they will learn. In PBL, learning begins with a problem and ensures the problem is related to learning. Students have responsibility for their own learning and collaborate through discussion. Teachers act as facilitators, design lessons, and help students develop strategies. Students use intelligence to ask questions, think, do research, and interact. Advantages of PBL include increased student motivation and activity, and experience with organizing projects. Disadvantages can include the long time needed to solve problems, requirements for more money and tools.