I wish I had more time right now to do a deep dive into this stuff, because it really touches many issues I am interested in. Lilia is making a difference between novice learners and advanced learning. I would also differ what is to be learned individually or in groups. In other words: How well is the problem defined that is supposed to facilitate learning. With ill-defined problems there is much need for the social side of learning, because everyone can (and needs to) reassure assumptions by communicating with other members of the learing group.