Vera Rubin, astronomer and Senior Fellow in the Department of Terrestrial Magnetism at the Carnegie institution of Washington had this to say, and I love it:
I would like to see a multilevel book, written for toddlers, schoolchildren, college students, and adults, that would look at the world around us and answer questions that youngsters may or may not ask as a day progresses. ... Each page off a tall book might have four sections, top to bottom, with the first answer being for the child, the second answer for those a little older, the third a "scientific explanation," and the final one a philosophical discussion of pertinent concepts like forces or brains or animals. Alternatively, there could be four pages per question, each page hidden behind the first...."
I read this just as I was hitting the midpoint of Neal Stephenson's The Diamond Age (more on that soon), and the convergence was frustrating. Exhilirating, too, but 'frustrating' because this multilinearity would be so easy to do, so valuable, and yet it really isn't done. For lack of a better term, I'm going to call it 'tiered engagement' and attempt a definition.
Beyond the cut: Definition and discussion