For the past three decades I’ve been working to dispel myself of an illusion that’s hard to recognize and even harder to overcome. I call it the “Illusion of Understanding.” It’s the false belief that we understand something but then we discover we actually don’t. The example problem below will help clarify what I mean.
http://theeducationscientist.blogspot.pt/2014/02/khan-academy-and-illusion-of.html