Book excerpt: How do you tailor education to the learning needs of adults? Do they learn differently from children? How does their life experience inform their learning processes? These were the questions at the heart of Malcolm Knowles’ pioneering theory of andragogy which transformed education theory in the 1970s. The resulting principles of a self-directed, experiential, problem-centred approach to learning have been hugely influential and are still the basis of the learning practices we use today. Understanding these principles is the cornerstone of increasing motivation and enabling adult learners to achieve. The 9th edition of The Adult Learner has been revised to include: Updates to the book to reflect the very latest advancements in the field. The addition of two new chapters on diversity and inclusion in adult learning, and andragogy and the online adult learner. An updated supporting website. This website for the 9th edition of The Adult Learner will provide basic instructor aids including a PowerPoint presentation for each chapter. Revisions throughout to make it more readable and relevant to your practices. If you are a researcher, practitioner, or student in education, an adult learning practitioner, training manager, or involved in human resource development, this is the definitive book in adult learning you should not be without.