A post in Professor Doom's blog contains the following exchange:
Pitchman: “What we know for sure is, the students who score high enough for College Algebra usually took courses past College Algebra in high school. The students who don’t quite make it into College Algebra took it in high school, and so on down the line.”
Faculty: “Wait a minute. You mean there’s hard evidence for what we know to be true: that to achieve a goal in learning, you must push past that goal to succeed? Why haven’t these results been published?”
The general idea seems to me to be that if one wants to increase one's comfort with problems at a particular difficulty level, then one should do problems beyond that difficulty level.
Is there a name for this effect? And if so, what are the key findings?