" . . . We may try to impose some kind of hierarchical, linear order on it, but the online medium remains essentially hypertextual. Just as the basic unit of hypertext discourse is the "chunk," a screenful of text or graphics, the basic unit of online learning is some kind of freestanding idea, almost like a sound bite. It may link to other related concepts, but arbitrarily. The student may choose some personal, even perverse sequence of learning. We can't do much about it unless we undercut the whole principle of hypertext and parcel out our chunks of knowledge in a calculated, teacher-controlled sequence."