Desirable Difficulties:
Why harder learning lasts longer
The counterintuitive truth: conditions that make learning harder often make it more durable.
What are Desirable Difficulties?
Coined by psychologist Robert Bjork, desirable difficulties are conditions that make learning more challenging in the short term but enhance long-term retention and transfer.
The key insight: what feels hard during practice often leads to better outcomes. Conversely, what feels easy and fluent during study often fades quickly.
This doesn't mean all difficulty is good—only difficulties that can be overcome with effort and that engage the learner in productive processing.
Types of Desirable Difficulties
Each one seems counterproductive—but research proves otherwise
Testing over re-studying
The struggle to retrieve strengthens memory more than the ease of recognition
Example: Quiz yourself instead of re-reading notes
Spacing over massing
Forgetting a little and relearning builds stronger traces than cramming
Example: Study in short sessions across days, not one long session
Interleaving over blocking
Mixing topics forces deeper processing and discrimination
Example: Practice different types of problems together
Generation over reading
Creating an answer yourself is harder but more memorable
Example: Try to solve before seeing the solution
What Feels Right vs. What Works
Our intuitions about learning are often wrong
How Cruxly Incorporates Desirable Difficulties
Cruxly is designed with desirable difficulties built in:
- •Testing over review: Every interaction is a quiz, not a re-read
- •Spaced practice: Reviews are scheduled at optimal intervals
- •Varied question types: Multiple choice, fill-in-blank, and more create interleaved practice
- •Generation required: You must produce answers, not just recognize them
The difficulty is built in—all you have to do is show up and practice.
FAQ
How do I know if a difficulty is 'desirable'?
A desirable difficulty slows learning temporarily but improves long-term retention and transfer. If something is hard because you don't have prerequisites, that's not desirable—it's just hard.
Can studying be too difficult?
Yes. If you can't make any progress, the difficulty isn't desirable—it's overwhelming. Desirable difficulties should be challenging but achievable. You should eventually succeed.
Does this mean I should make everything harder?
No. The goal isn't maximum difficulty. It's optimal difficulty that leads to successful retrieval with effort. The struggle should be productive, not frustrating.
Why does effort improve memory?
Effortful retrieval strengthens neural pathways more than easy recognition. Your brain treats difficulty as a signal that information is important and worth retaining.