Which is a better way to learn new material?

In my opinion, learning a larger range of material will get you going a lot more efficiently than slowly learning a single aspect. A larger range will make it harder to remember things, but you can always go back to Treehouse for reference until you completely understand it.

This will always come down to the person. You have to evaluate the way you learn best, and apply it to what you are learning at the time. I get bored easily if I am not creating something, so a project based learning environment is great for me. Others are fantastic with definitions and theory, and don't need to be using the stuff to understand it; that is a fine way of doing things as well. Of course, some people need and do both -- the dichotomy I created is a gradient of sorts. Dynamic learning comes from exposure, explanation and experimentation.

Teaching is always a challenge because of these broad spectrum; it's why so many children fall through the cracks of my towns school system. It gauges intelligence through tests. Some kids aren't great test takers, and fail and feel inferior. They perhaps would excel in an art class, or a mechanics class or something else, because they learn and succeed in different ways.