The platform is "a simple tool for specialized subjects where there isn’t a textbook, and knowledge advances quickly."
There is a lot of talk about redefining the textbook. Big publishers have been creeping toward etextbooks for a while and Apple shook things up with iBook 2 and iBook Author.
But, we don't need to redefine the textbook. We have well-defined textbooks already. Adding interactive widgets and video doesn't make textbooks conceptual any different. What we need is some other way of delivering content, something in between raw, primary source information such as what is found on Twitter and academic research found in academic journals on the one hand and the heavily curated and edited material in a traditional textbook. The first is undifferentiated and unqualified, the latter lack freshness and can be either ponderous or facile.