This is so on point. "Some learners may find it difficult to develop informal relationships in an e-learning environment." I learned early in my career that students are timid and shy. If they do not want to engage, they won't and their academic progress can suffer if they are not following up with the instructor. I usually try to stay in touch via emails and messages. This sometimes helps, but there are times I've had students refuse to engage altoghter. This is when having a strong online support team comes in handy to support my efforts.
