Why Difficulty Is the Point
The study methods that feel most productive while you're doing them are, reliably, the ones that leave the least behind afterwards. The ones that feel like a struggle are the ones that actually work. That's probably the most counter-intuitive result in the whole field, and it's the one nearly every study tool is built to violate.
Retrieval against rereading isn't a close contest
Reading a chapter for the second time is a pleasant experience. Shutting the book and trying to haul it back out of your head is not. But retrieval is what strengthens the memory, and by a wide margin, compared with restudying the same material for the same number of minutes (Roediger and Karpicke, 2006).
The bit that took me a while to properly absorb is that dragging something out of memory is what makes it easier to drag out next time. The effort isn't preparing you to remember later. The effort is the remembering being built, right then, while it's uncomfortable.
The purest version of this is the blank page: write down everything you can recall about a topic with nothing in front of you and no prompts of any kind. It's the most effortful retrieval format that exists and it's also the most effective one, and it's genuinely horrible the first few times you do it properly.
Desirable difficulty
There's a proper name for this, desirable difficulties (Bjork and Bjork, 2011), and the finding is that putting the right sort of struggle into practice, retrieving rather than reviewing, spacing sessions apart, mixing problem types together, gives you better long-term retention and better transfer than smooth easy conditions do.
"Right sort" is carrying weight in that sentence. The difficulty has to be one that effort can actually overcome, not a random obstacle in the way. Nobody learns more because the PDF wouldn't load. But inside that band, harder really is better.
Two of them are worth building your revision around directly.
Spacing. Cramming works right up until the exam and then falls off a cliff. Reviewing something just as you're on the edge of forgetting it resets the forgetting curve and flattens it a bit further each time (Ebbinghaus, 1885), which means the gaps between your reviews are supposed to be growing rather than staying fixed.
Interleaving. Grinding one topic to exhaustion before you start the next feels orderly and organised, and it quietly trains your brain to expect what sort of answer is coming next. Mix related topics together and you're forced to work out which idea even applies before you can apply it, which is the thing an exam is genuinely testing (Rohrer and Taylor, 2007). It feels worse and it scores better, which by this point in the post is the recurring theme.
Conditions that make performance improve quickly during practice often fail to support long-term retention. Conditions that feel harder often support it best.
The fluency trap
Here's why any of this matters outside a lab. Ease produces fluency, so the material starts to feel smooth and familiar, and fluency feels almost identical to mastery from the inside while not being it at all (Dunlosky and Metcalfe, 2009).
Which gives you two students. One has reread a chapter three times, feels ready, and isn't. The other has just spent fifteen minutes losing a fight with a blank page, feels shaky, and is in considerably better shape. The feeling and the reality are pointing in opposite directions, and almost every tool that optimises for a pleasant frictionless experience walks its users straight into that gap without ever intending to.
Effort isn't the price you pay for learning. Effort is the learning. Take it out and you've taken out the part that works.
None of this means studying is supposed to be miserable, and there's a real difference between productive difficulty and just suffering. The moments that feel like a struggle, the blank page, the spaced review you'd rather skip, the mixed problem set that keeps catching you out, aren't obstacles sitting in front of the work. They are the work. What a tool can reasonably do about that is make the struggle survivable rather than absent, which is the good kind of hard, as opposed to the panic cramming manufactures at two in the morning.
Sources
- Bjork, E.L. and Bjork, R.A. (2011) 'Making things hard on yourself, but in a good way: creating desirable difficulties to enhance learning', in M.A. Gernsbacher, R.W. Pew, L.M. Hough and J.R. Pomerantz (eds.) Psychology and the Real World: Essays Illustrating Fundamental Contributions to Society. New York: Worth Publishers, pp. 56–64.
- Dunlosky, J. and Metcalfe, J. (2009) Metacognition. Thousand Oaks, CA: SAGE Publications.
- Ebbinghaus, H. (1885) Über das Gedächtnis: Untersuchungen zur experimentellen Psychologie. Leipzig: Duncker & Humblot. (Translated as Memory: A Contribution to Experimental Psychology.)
- Roediger, H.L. and Karpicke, J.D. (2006) 'Test-enhanced learning: taking memory tests improves long-term retention', Psychological Science, 17(3), pp. 249–255.
- Rohrer, D. and Taylor, K. (2007) 'The shuffling of mathematics problems improves learning', Instructional Science, 35(6), pp. 481–498.
Read more
- Why the fluent, familiar feeling of knowing something isn't evidence you know it: The Feeling of Knowing
- Why guessing before you study, even wrongly, beats studying alone: Be Wrong First
- Why AI tools that do the work for you quietly take the learning with it: The Simplification Trap
- The four brain-level pillars of learning: The Four Pillars of Learning