Reward the users that answer questions and mark them as trustworthy.
1) Eliminate the ability to up/down vote your own post. If I see an answer to a question, and it has been upvoted once, I don't know if someone else has effectively said "Yes, this person knows what they are talking about and I agree that this answer is correct" or if the person is just full of themselves and automatically upvotes their own post.
2) 99% of questions that I have which I can't answer on my own, are answered by users. After being here for a few months, I can list 5-10 people that regularly, and I mean regularly, answer peoples questions. German = christian, siebolt, wataya are the first that pop to mind (sorry for leaving some out!). In the French lessons, hands down, Sitesurf owns the questions/answers department. These are users that go out of their way to help us learn. Perhaps there is some way of "rewarding" them. For example, give users points for upvotes received. I know points don't mean anything, but if someone is into that (trying to get the "high score" amongst their friends), then it would encourage them to help. Sitesurf would probably have well over 100 000 points just from answering questions.
3) If not points, then maybe a new "point" category....like brownie points, or beer mugs or something, that not only show our appreciation to them, but will also show to someone new that "hey, this person is generally considered to be knowledgeable and you can probably trust what they're telling you". I'd sooner trust one of them then a random "stranger" that gave me an answer until they were proven to be knowledgeable.
Anyways, I don't know if that makes sense, but it's just a thought. Hats off to the helpers!
I've learned a lot from the comments. It's sort of funny because the whole comment thread may start because someone was upset with what drivel duolingo concocted, but then, someone explains how it should be said, or explains the seemingly bizarre idiom, and I end up really learning something.
And, yes, there are certain individuals who provide high quality explanations in the comments. And, I do wish they could be recognized for their efforts.
Looking at this thread I'm a little puzzled.
I can see where you can vote for the best individual effort in the two or three general translation exercises that are given in each group and I can see where each question in a learning exercise can be commented on in the comments section.
Maybe I'm missing something obvious, but I haven't noticed that you can vote on comments in those threads. And I haven't noticed that you can do anything other than vote for the best translation in general translation exercises.
So I don't know what everybody is getting at on this thread about voting for the best comment.
"Voting" meaning upvote/downvote arrows under the comments.
Forget the translation section. If you're doing a lesson, and you have a language question about the sentence, like "Why is xxxxxx conjugated that way?" or "What purpose does xxxxxx have in this sentence?", you post it in the comments section. Then, people respond to your questions. If I come back to the question 3 days later and there are 2 answers to my question, 1 with 8 "upvotes" and 1 with 5 downvotes (-5), I will assume that the Duolingo community has seen the answers given, and the majority agree with the explanation given by the person who has 8 upvotes, and they think the person with -5 is totally wrong. If I asked in the French community "Is a female dog called "la chien"?" and someone said "Yes, all you have to do is put "la" in front of the noun and it is feminine", that person doesn't know what they are talking about and they should be downvoted into oblivion. I can think of two people that regularly post answers to questions that don't know what they're talking about and seem to be giving advice because they think they're right or they're intentionally being jerks. If someone regularly gets downvoted (and I can readily see that by the possible rating system I suggested "brownie points" or whatever) then I'll be a lot more careful as to whether I believe them or not. If someone has a billion "brownie points", I'd be a heck of a lot more ready to take what they say as fact.
The upvoting/downvoting system works fairly well, but what if I get an answer from just one person and after a week there are no upvotes/downvotes to their response. What if it isn't really a question you can readily look up on the internet to see if it makes sense? Like the use of a certain word colloquially, or an idiom etc... If they tell me that "tastes like a bag of hammers" is an English idiom, and their "brownie points" indicate that they stand at a -274, I'll disregard what they say.
As for the random comments, like "OMG, this sentence talks about cats and I have a cat too! :)" Those comments should be downvoted to oblivion too. You aren't contributing anything to the Duolingo society, stop polluting the comment sections with your chatter. Take it to facebook or twitter, or put it in your personal update box.
Maybe I'm just a grumpy dink, but when I try to help people out by checking comments so that I might possibly provide an answer, and there are 5 comments of "OMG" and "LOL" and not even a question in the first place, I lose faith in humanity.
Hope that clarifies things.