Kinds of Learning: Immersive, Structured

My supervisor, Gord McCalla, told me about an invited talk that was given at AIED one time by John Sellers (?).  In this talk, there was a discussion of two kinds of learning:

1. like language learning, where you just put yourself in a rich environment and you pick it up as you go
2. where it takes hard work, reflection, organized/structured approach to material

I've Googled around but I can't find any references to this talk.  If I ever find it, I'll put the link here.

I think this discussion is interesting because it could inform the kinds of instructional planning approaches that should be used for certain domains, or even certain learners in certain situations.