This is a potential problem I've observed longer than a year. I asked about this during the recent election, but it was a late post and it didn't get enough votes to be included in the questionnaire. So, it has never been answered, and many may not even have seen it.
The problem is anyone can post an answer. It doesn't matter who we are--a native speaker, a teacher, a learner, a non-native speaker, anyone. This is the spirit of SE, and I don't ask us to change that. But as a result, we get a not very good (sometimes blatantly wrong) answer written by a learner or a non-native speaker every now and then.
This should be fine if voting on ELL works perfectly.
But as everyone seems to agree, our voting is not perfect, so it's not that rare that an incorrect or weak answer gets lots of upvotes, which may give the false impression that the answer is correct.
I'm not saying that only native speakers can write good answers, but if we don't want to fool ourselves, I think we'd all agree that many of our answers written by learners or non-native speakers (yes, I'm one of them) are just plain wrong or, in the milder cases, weak. (It's one of the reasons I've been trying not to post answers too often, and I try to be as careful as I reasonably can when I post comments.) Here is what I wrote in a comment earlier today:
Posting an incorrect answer in an authoritative voice, and continuing to fix it until it gets right according to comments from others shouldn't be encouraged, in my humble opinion. It can give false illusion. It can decrease the chance that the OP can get a good answer in the first place (because people tend to skip answered questions in small communities). And it can affect the quality of our site as a whole.
(A user kindly commented on my comment Sir, isn't it better to come up with the precise answer then criticising someone? [sic] -- Let me be clear. I didn't aim it at someone specifically. I don't even like to write anything like that, but when it keeps happening all the time on a site that I care, and I think we all care, I think I have to say something. If it was criticizing, which I don't think it was, it was for everyone of us, not just someone specific.)
So, here is my open question:
How can we help our learners and non-native speakers avoid posting weak or incorrect answers?
If there is no good answer to that, I'd like to make a plea:
To all ELL fellows, please refrain from posting answers based on your thoughts when you know you don't know the answer, or know only part of it, or it's just an idea or an opinion. Please keep in mind that reputation points are fun, but quality of the site as a whole is more important. (Isn't that why we're all here in the first place?)
However, if you've done some research on the topic and found what you think is a good answer and want to share, please do! Just make it clear that you didn't come up with it on your own; that it's not just your intuition. (And don't forget to cite your sources appropriately!)
But what if all you have is your own intuition, which you think is right!? Maybe you've heard someone use it that way, so you sort of "know". And you want to help? -- It's your choice: you can leave a comment, or you can post it as an answer, but please make it clear that it's your opinion.
Also, please be more careful in comments, because we can't upvote or downvote comments. This doesn't mean that we shouldn't help each other out by leaving our opinions entirely, but when we're not sure, it's better to make it clear that we are not sure. In other words, please try not to sound authoritative when we know that we do not deserve it yet.