Principle 01
The testing effect[1]
Retrieving a fact from memory strengthens it far more than
re-reading or reviewing it does — even when re-reading feels more
productive at the time. Students who are tested on material
repeatedly outperform students who simply restudy it, and the gap
grows wider the longer you wait before the final test.
What this means for Edubba
Every card is a typed retrieval attempt, not a flip-and-reveal.
There's no version of the product where a student can review
passively and count it as practice.
Principle 02
The spacing effect[2]
A landmark analysis spanning over 800 experiments confirmed that
spreading practice across time produces far stronger long-term
retention than massing it into one session — and that the ideal
gap between reviews grows as the material becomes better known.
What this means for Edubba
The five-box system locks a set after each session and reopens
it on a delay that lengthens automatically as cards move up.
Cramming a set repeatedly in one sitting isn't just discouraged —
it's not possible.
Principle 03
Desirable difficulties[3]
Robert Bjork's framework identified a category of learning
conditions that feel harder and slower in the moment — effortful
recall, delayed practice, no shortcuts to the answer — but produce
stronger, more durable memory precisely because they're harder.
Conditions that make learning feel easy tend to produce fluency
that doesn't survive a delay.
What this means for Edubba
One canonical answer, exact recall, no hints, no peeking. If a
card feels effortless to get right, it's usually a sign the
method has been softened somewhere — which is exactly what we
designed out.
