Ah that's a good point that both you and scottcha make regarding the typing strengths/weaknesses of children, which would make a typing-based approach maybe non-practical. I guess more generally what I was trying to better understand was whether or not the use of these fitted blocks (as I understand Scratch to do) has been studied enough to be considered more fruitful in developing an understanding of rudimentary programming rather than a more free-form way of doing so (maybe just blocks that can be combined in any way, even if they don't work as intended). Maybe said a slightly different way: why did MIT researchers choose to use a "coloring in the lines" method (which may hinder creativity and potentially interest)?