This study presented by Betsy Bannier highlighted the key elements to engaging adult undergrads and promoting their success.
The key elements listed by Bannier:
Offer Problem-Based Learning Experiences
Identifiy the students' motivation (extrinsic/intrinsic)
Identify the students' Help-Seeking Behaviors
Remain flexible with due dates
Explain relevance of the course content throughout session
Identifying the "adult learner" by their social experiences (marriage, parenting, military service...) rather than by chronological age made sense to me. I appreciate her attachment to her individual students - though she was completely physically removed from them. It minimized my concerns for loosing the energy and connection that an on-site course provides.