This article is specifically about online learning. Consider how the approaches and principles might apply to other learning environments.
Cercone, K. (2008). Characteristics of adult learners with implications for online learning design. AACE journal, 16(2), 137-159. https://www.learntechlib.org/primary/d/24286
One of the key aspects of adult learning is the recognition that adults are often in a position where they are juggling various commitments, priorities, and stressors. All of this means that cognitive capacity is often full even before they engage in learning. (Do you feel this?) Understanding cognitive load theory and its implications for instructional design are key skills for supporting adult learners.
Zach Groshell. (2021, February 8). Cognitive Load Theory, Executive Function, and Instructional Design. Education Rickshaw; Education Rickshaw. https://educationrickshaw.com/2021/02/08/cognitive-load-theory-executive-functioning-and-instructional-design/