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Spaced repetition

Is Duolingo using some kind of spaced repetition algorithm? ( http://en.wikipedia.org/wiki/Spaced_repetition )

Sometimes it doesn't feel like it when I get asked again and again easy words that I never fail, but almost never get asked those really hard to remember words.

6 years ago


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Yes, Duolingo does use a spaced repetition system for the daily practice.

6 years ago


What spaced repetition system do you use? I've used Supermemo and Mnemosyne for many years. I am new to Duolingo (I now learn French). Duolingo looks very promising. I will combine it with Mnemosyne to get the best of both.

HenrikMG (Oslo)

4 years ago


I'm still having the same issues as described in my original post.

There are these few sentences I get constantly wrong yet Duolingo asks them very rarely. And then there are a couple of sentences that I'm asked almost daily and never answer wrong. I love Duolingo a lot but the spaced repetition implementation might need some improvement. Or maybe it's just an issue with my account?

For contrast I use Anki regularly and it's algorithm works flawlessly: failed sentences are repeated more often.


5 years ago


This bug hasn't been fixed yet!!! Why not use a simple algorithm such as Anki's? That one you guys are using is terrible.

1 year ago


I'm curious about this one, too. I worked with creating spaced repetition algorithms based on a logarithmic distribution of real-number Leitner boxes, and I'm curious what they use here.

6 years ago