Justifying layering

I have this personal expectation that may annoy others. When I propose a learning activity, I feel I should explain why it works and what need it meets. This is kind of the way researchers look at application issues. I understand that technology offers some very interesting possibilities, but there should be a logical justification for why possibilities are implemented.

The following is a video I created to accompany the series of posts and a book on Layering for learning. The previous posts have mainly outlined the learning activities that can be applied with layering techniques and provided tutorials for several layering services. You can locate the previous posts using the layering tag associated with this post. This post is more about justifying these techniques.