Illusions of fluency represent one of the foremost challenges we face in helping students learn subject matter deeply. Anyone who has taught for more than a year or two has encountered the befuddled student who comes to office hours after an exam or assignment and explains that he studied the material for many hours and thought he had it down cold. Such a student is laboring under the illusion of fluency, possibly because he engaged in common study strategies like reading the textbook or reviewing his notes over and over again.
