Why is it so hard ?
At least in math, spotting areas of difficulty for students based on data on previous exercises and data from other students does seem possible.
At least in math, spotting areas of difficulty for students based on data on previous exercises and data from other students does seem possible.
These systems rely on humans to curate the conceptual difficulties associated with each problem separately, but those lists are never complete and often just confuse the student further.
Some systems don't even try to do what you're suggesting, and just give students the "right" way to solve the problem at hand after a certain number of attempts. These are by far the worst, as it's painfully easy to game the system.