Questions repeated too many times in an exercise.
When I am strengthening sections I have already done, it asks me the same question over and over, sometimes in a slightly different way, but usually the exact same 3 or 4 questions coming up again and again with no variation. I have been trying to stick with it but I am bored of saying "He must call his daughter" or "it is Wednesday" over and over. There are lots of words and sentences that I don't get to practice anymore because of the repetition of a few. I cant even be bothered putting in the accents on the repeated questions now, which is lazy but I got it right like 2 seconds ago so doesn't feel like it matters anymore :(. Saw complaints about this from about 4 years ago but it has never been a problem for me before the last couple of months. Apologies if someone has complained about this more recently, I cant see a post about it.
I feel like that episode of Dexter's Lab where he just says OMLETTE DU FROMAGE over and over again forever. Please fix this, I am very ready to give up on Duo.
I experience the same - and it is IMHO waste of time if you get asked the same stuff over and over again even you got it right.
And then there is the stuff which you answered wrong - and you might not get asked these questions / words in the same review session or in a different context (depends).
Memrise does like that with the 6-step flower planting process.
You do not see it the first time.
For Memrise review sessions it asks you the word / phrase YOU GOT WRONG multiple times and counts how many times you get the 2nd/3rd repetitions wrong or right.
That is IMHO better than repeating the stuff which you got right in the first instance.
For the moment I have to review +250 words in two Portuguese courses.
Of course I do not get all Memrise review vocabulary 100% right.
So even THAT annoys me, that I can not go strictly through the list and test all words if I know them and repeat those words 2nd/3rd++ times I got wrong in the review phase.
It is way too time consuming to have to answer words 2-4/5 times again and over again, especially with so many 500++ words on the stack.
For DuoLingo first time learning (new) sessions (N O T strengthen excercises), I guess it is a good thing, that it asks (should ask) the exact question or the words in a slightly different context (the latter is IMHO even the better concept; often it does not :() 2-3 more times, to really hammer it into your head.
Memrise even improves this 1-2/3 times Duo concept by doing it exactly 6 times (flower planting).
Summary: I have to agree. The concept / algorithms could be improved throwing into much more "weak/always got wrong/difficult" vocabulary, you may also have learned 24-48 hours ago (or you did not even complete the full skill, e.g only lessons 5/10 finished).
At least this works IMHO much better on Memrise (3-6/8h, 12h, 24h++) with the additional short-term review cycles - including 25/50/85% finished levels.
The review cycles will only expand if you get those learned words right.