Four Conditions For Practice

Your routine: every evening you open a problem from a list curated to sit just above your current level, think for 15 minutes, and if you have not solved it you read the editorial, nod, close the tab, and move on. Three months of this and your rating has not moved.

Norvig quotes the conditions for effective learning: a well-defined task, an appropriate difficulty level for the individual, informative feedback, and opportunities for repetition and correction of errors. Which conditions does this routine fail? Select all that apply.