Determining whether a post should be marked as a duplicate

Question

Should questions be marked as duplicates, even if the duplicate thread did not really provide a good answer? To me, this just does not make sense. The fact that there are answers, in general, means nothing, and an accepted answer just means that it worked for the person who asked (according to the tour). So, at times, it can make perfect sense to ask a duplicate question.

For example, consider something like: "I read the answer to [insertPostHere], but did not really understand the explanation, could someone please elaborate?"

I doubt many people would vote to close the above. Despite some posts not containing references to other questions, I personally feel that quite a few posts are marked as duplicates and when I look at the answers in some of them, I just think: "Well, there is no way that someone who is obviously a confused beginner is going to understand the given explanations."

If they should be marked as duplicates, are we supposed to talk with the OP through the other thread or chat to communicate with them if they have an issue that the duplicate thread did not solve?

EDIT:
What if the new thread just has better answers and more attention than the old one. Why wouldn't we close the old one and point it to the new one?

Answer 1

are we supposed to talk with the OP through the other thread or chat to communicate with them if they have an issue that the duplicate thread did not solve?

If there is an issue that the duplicate thread did not solve, then ask a new question, link to the duplicate, and explain what you've learned from it, and where you need information beyond what's already there.

This is what's also stated in the banner displayed below posts marked as duplicates. I emphasized the important part:

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

If it's just about a minor thing, you can always add a comment under the answers you don't understand, given you have enough reputation to do so.

Finally, you could place a bounty on the other question, which could be used to draw attention to the post and update the existing answers if they're outdated—or request more details.

What if the new thread just has better answers and more attention than the old one. Why wouldn't we close the old one and point it to the new one?

That's perfectly valid to do. The end goal is to just point users to the best possible answer. The chronological order of posts doesn't matter, really.

Answer 2

I read the answer to [insertPostHere], but did not really understand the explanation, could someone please elaborate?

That's a valid new question, provided that you are clear and specific -- most importantly -- about what you do and don't understand, and also the reason you're looking into this in the first place, maybe how you tried to apply the information in the answer, and so on.

"I don't understand $SITUATION" is a perfectly appropriate start point for a Stack Overflow question, but just because $SITUATION is another SO question doesn't mean the rules are relaxed for this post. You still need to show some effort and write intelligibly, just as you would for anything else you wanted to ask.

That accomplished, the question would be its own porblem, with no reason to be closed as a duplicate.