The idea that instructors are somehow incapable of violating basic instructional design principles is naive. What percentage of our nationwide faculty has heard of the split-attention effect, redundancy principle, contiguity principle, cognitive flexibility, or even cognitive load? Now, instructors are expected to be subject matter experts and instructional designers. The two are not synonymous, and the results can be detrimental to learning. iBooks Author is giving creative license to everyone, with or without instructional design experience.
Sounds elitist, doesn't it? "Everyone, with or without instructional design experience." Why, just imagine what would have happened if we'd allowed people withoutformaltraining to compose and record music :-). But there's an important difference: you don't have to listen to my music , but students have to use the textbooks their teachers tell them to . I know there are a lot of lousy textbooks out there, but at least most of them went through some kind of editing, and had at least one pair of professional eyes look them over. The human cost of crowd-sourcing free-range textbook review, the way we crowd-source video reviews on YouTube, seems high to me...
Later: coincidentally, I stumbled upon this invitation to hack a Computing 101 textbook in Boston on March 8. Listen to the video around the 33 second mark: "One [goal] is to construct a sensible table of contents: easy." With respect, no, it's not: just look at the diversity of content in some greattextbooks that are already out there, or have been party to all the wrangling that's gone into curriculum recommendations. "Massive collaboration will solve our educational problems" is no more valid than the "technology will solve them" mantra that Audrey Watters and others have criticized so cogently.Still later: Audrey Watters quoting Connie Yowell at DML2012:
Failing fast and failing often: not really such a great idea in high-stakes environments w/other people's children.
 Well, everyone affluent enough to be connected. And living somewhere free enough that they can speak their mind without fear of arrest (or worse). So OK, not "everyone".
 Unless you're Canadian, and too polite to ask me to please turn off my damn iPod, or jeez, maybe just switch to CBC, because what is that noise? Peruvian heavy metal? You're joking, right? You're not joking.
 OK, they don't have to, but it makes passing the course is easier/less work, particularly if the teacher is text-centric.