How to choose a duplicate target?

Question

After replying to this recent question:

Why 的 in reduplication of adjectives “Noun + Adj + Adj + 的”?

I thought to myself that something like this must have been asked already. A quick search revealed this potential duplicate here:

Adverbs of degree with reduplicated adjective phrases?

Assuming that these two questions are actually duplicates, what's the rule of thumb, or community consensus, for deciding which one to choose as a duplicate target, and which one to close?

Answer 1

Finding duplicates is not an easy task: it requires both topic expertise and familiarity with the site. There's a rule-of-thumb over at meta.SE:

Questions may be duplicates if they have the same (potential) answers. This includes not only word-for-word duplicates, but also the same idea expressed in different words.
_{How should duplicate questions be handled?}

Which seems consistent with the message given to duplicates ("This question already has an answer here"):

Identifying borderline duplicates is challenging: it's an opinion. It's particularly difficult in cases when they partially overlap, which seems to be the case for the given question. How it could end up closed:

• The OP can "accept" their post as a duplicate, and the post is closed as a duplicate.
• The question could accumulate 5 close votes that identify it as a duplicate. (Or even just 5 close votes, of which the majority identify it as a duplicate).
• A diamond moderator might diamond-hammer close it as a duplicate.

(Users with a gold tag badge get their own form of hammer closure, although I don't think anyone here has such a badge yet.)

---

What else?

• Don't be too afraid to vote to close a suspected duplicate (you don't need to be ~100% certain, unless e.g. you have a diamond hammer). It creates a useful sidebar link between the two questions, and it's why we have the whole voting process. It'll help the voting process if there is a comment explaining how it is a duplicate.

• Duplicates are not necessarily bad, and sometimes function as useful signposts for future readers (in which case, they should not be deleted).

  One thing I want to be clear about, though, is that duplication is not necessarily bad. Quite the contrary — some duplication is desirable. There’s often benefit to having multiple subtle variants of a question around, as people tend to ask and search using completely different words, and the better our coverage, the better odds people can find the answer they’re looking for. And isn’t that, really, the whole point of this exercise?
  _{Dr. Strangedupe: Or, How I Learned to Stop Worrying And Love Duplication, 2010}

• Improved tagging facilitates identifying duplicates.

  We rely on Stack Overflow users to tag these questions appropriately so they naturally “group” with the questions they’re related to. The more tags the questions have in common, the more likely they are to show up together on the related questions sidebar.
  _{Handling Duplicate Questions, 2009}

  I go further and say to facilitate identifying duplicates, we should also:

  1. Improve question titles, which makes it easier for everyone to identify duplicates.

  2. Ensure there is one question per question. There's a close reason for this:

     Needs more focus

     This question currently includes multiple questions in one. It should focus on one problem only.

     For example, if one question asks about A⋃B, one question asks about A⋃C, is one a duplicate? It's hard to tell. But if one question asks A, another asks A, it's easy to tell it's a duplicate.

     The fact that the OP in the listed question needed follow-ups to every answer, and the fact that the question body contains four question marks, indicates it's not clear. There seems to be some question the OP wants answered, but didn't ask.

• Diamond moderators can merge questions, but it's messy (the old post still exists but redirects, etc.):

  Questions should be merged if one question is an exact duplicate of another (i.e. when its answers would make perfect sense on the other question), and its answers are high-quality and valuable enough to be included on the other question itself, so that good answers aren't forked across multiple copies of the same question. In order to merge a question, the question to be merged must first be closed as a duplicate of the intended merge target.
  _{What is a “merged” question?}

  We might merge questions like "what is the difference between 还是 and 或者?" with "what is the difference between 或者 and 还是?" But it's probably better to just use the duplicate process and not merge.

• It's okay to close a question as a duplicate of a newer question which might be better written or have better answers.

Answer 2

The two questions mentioned are slightly different. One was asking why the adjectival marker 的 is needed in reduplicated adjectives, another one is asking why adverbs of degree like 很 (very) are not used on reduplicated adjectives. The two questions were answered differently.

But it is beside the point. There are actually many duplicated questions. When I see a question that seems familiar, I would do a search to see if an existing answer from a similar post would answer the new question. If I found one, I would vote to close the new post. If the new post had already generated the best answer for the questions, I would post a link to the older post and vote to close that post instead.

I wonder if we can have a merge posts option, that merges the newer and older post into a single one.