Why does duolingo "drain" sections I just recently learned??

[SilkyFrench]

Can someone please explain the algorithm for Duolingo "draining" sections that I've learned? It seems super random and is quite annoying to be honest. I understand that we should be always reviewing things we've learned but this appears to just be random programming.

[pentaan]

Here is the link to an explanation
http://duolingo.wikia.com/wiki/Decay#Decay

[MaddieOlivia04]

When they "drain" your skills, it is because the words that you have learned will fade from your memory. I guess it is just a way to pressure you into being more consistent in your learning. You don't have to go over those skills again, but it will help you out in the long run!

[psionpete]

I believe it works on the strength of individual words in the skill. Each word weakens by a small amount each day. It also weakens if you need to look up its meaning or you get it wrong in a question. There may be other parameters but it is not random, although as they tweak the algorythm occasionally I can see it could look like it.

[OldPalHappy]

You can not hover over words, answer quickly, and answer correctly to strengthen more, else Duolingo will ask you to repeat lessons and words you had trouble with.

I also heard this might be an A/B test, and if so I guess you'd just have to ignore it at times, and continue when you think you're ready.

[vivisaurus]

Hi! You might find this explanation helpful. =]