I was one of the first, if not the first, to use the term eLearning . Take two groups of students. Tell the first group to read an essay and answer a set of questions about it. Tell the second group to read the same essay but tell them the material is terribly controversial. The second group will answer more questions correctly.
Uncertainty engages the mind.
Ellen Langer writes that uncertainty challenges people to refine and internalize their take on things. In the real world, everything flows. Nothing is certain. Meaning is relative. That which in itself has the highest use possesses the greatest beauty.