Malcolm Knowles was an American adult educator who is famous for developing the theory of andragogy. Andragogy refers to the process of teaching adults and focuses on the learner rather than the teacher. Knowles believed adults learn best when they have control over their learning. He identified four key assumptions about adult learners: they are self-directed, draw on life experiences, are problem-centered, and are motivated by subjects with immediate relevance. Knowles proposed six principles for adult learning, including involving learners in planning, acknowledging the value of experiences, addressing readiness to learn, and focusing on problems rather than content.