Direct experiences refer to first-hand experiences that individuals have in real-life situations. These experiences involve personal involvement and interaction with the environment, people, or events. Direct experiences provide individuals with firsthand knowledge and understanding of concepts and help in the formation of concepts and abstraction. They allow individuals to gather information, observe patterns, and make connections, leading to the development of higher-level thinking skills. Vicarious experiences, on the other hand, involve learning from the experiences of others, while indirect experiences refer to experiences that are not directly encountered but are gained through observation or second-hand information. Therefore, direct experiences are the most effective in concept formation and abstraction.