In corporate training the learning audience consists almost exclusively of adults. The field of adult learning was pioneered by Malcolm Knowles, who wrote the book The Modern Practice of Adult Education (1970). Subsequent research by others in the field has corroborated and extended these findings. Knowles identified a number of characteristics common to adult learners:

• Adults seek relevancy in their learning experiences. To invest effort into learning, the outcome should be directly applicable to something that they value, such as their careers. 

• Adult learners have a strong preference for self-direction. Instructors should involve the adult participants and facilitate rather than control the learning process.

• Adult learners are goal-oriented. Usually, when they enroll in a course they have a specific goal in mind. Adult learners prefer educational experiences that are structured, logical, and organized. 

• Adults learn best when they can apply life experiences during the learning process, e.g., work experiences, previous education, and personal history. They seek to apply the new learning in the context of their life experiences. 

• Adult learners in particular need to feel a sense of respect in their learning experiences. Adult learners should be allowed to voice their opinions freely in class, and should be treated as equals by instructors.

Instructional Designers should make the effort to gain an appreciation of the characteristics of adult learners, and apply this knowledge to the design of learning programs for adults.