Question about gold trees
I've just got a question about keeping trees gold:
Do the skills in the tree randomly start turning not gold or is it some sort of spaced repetition technique?
it's a spaced repetition technique, so things Duolingo's algorithm thinks you need to brush up on will lose their gold status, and then lose the strength bars over time, so you can either keep doing the strengthen exercises to bring everything back up to gold or focus on the specific skills.
I would say it may be rather random, if you compare DuoLingo's code to Memrise's SR defined and transparent algorithm, as their SR algorithm must be somehow broken, with:
words published in your "Words" tab list with wrong / not-updated "last_practiced" column (I can cleary see that the low strength or strength 0 (dead words) is wrong for MANY of the words in this list, as I practiced daily / weekly on DuoLingo and MANY are well familiar to me!!!)
Or: DuoLingo's user database for "learned words" is OK but only their "Words" vocabulary overview API stream is pretty much corrupted and published from a different source - but the staff does do not seem to be interested to fix it or at least try...
"Words" tab / vocabulary stream is missing 3+ grammar skills and ALL of contained words in my EN-PT tree
As others have said it is spaced repetition. The good thing about this is that doing several successful reviews on any one skill will make that skill less likely to appear again for some time.
It is also possible that later skills may have some bearing on earlier ones. If so, then strengthening later skills would be most advantageous for keeping the entire tree golden.
Check out this comment from a while back: https://www.duolingo.com/comment/6176795/Best-Way-to-Make-Your-Tree-Turn-Gold-and-Stay-Gold and his web blog http://gregreflects.blogspot.com/2014/12/how-to-make-gold-duolingo-tree.html
I'm not convinced it totally works, but it's fun trying.
I have the same question. I gave up un French and Spanish for a while because each day 5 or more would lose the gold Color, and sometimes I would have to do it three to five times for it to go gold again. For me that was way too much review, so I just let it go and stopped using Duolingo for a while. Especially the French and Japanese where I’m already very fluent. It was just a waste of time.