How to answer questions that are duplicates of many previous questions ?

Question

I couldn't find a duplicate of this.

In SO there are many questions which are exactly the same asked in many different variants and flavours and aren't closed as duplicates. Usually such questions will have plenty of answers, so may be that's the reason mods here don't want it to be closed. Once when I flagged such a question for moderator attention, the reply I got was "I think its better to let sleeping dogs lie". Ok, I have no issues with that.

My question is, how do I answer a topic or question which is asked as a separate question on SO, which is essentially the same as a previous question, if I have an answer not posted til now for it?

Here are the options:

1. Post answer in the oldest thread.

2. Post answer in the most visited/answered/active thread.

And then:

a. Post a link to my answer as a comment in remaining threads.

b. Post a link to my answer as an answer in remaining threads.

c. Duplicate my own answer as answer in every thread (But I have seen users discouraging this)

d. Vote for all duplicate threads to be closed.

Which should I go for?

Answer 1

My view: post one answer in the "best" existing question, where best is a weighted combination of:

1. Most good/useful answers
2. Clearest asked question

noting that (2.) is easiest to be improved by editing if there is a large disparity between the two.

Then for the remaining questions, in order of preference:

1. Close as exact duplicate those which genuinely are.
2. Post a new answer, which is specific to the differences between the two questions, referring to the canonical answer for the generic parts. Don't duplicate content, supplement it.
3. Post a comment referring to the canonical answer and explain (e.g.) how it's a strongly related problem.

Duplicating content results in what amounts to an update anomaly in database speak. Closing things as exact duplicate where the link is not clear is bordering on RTFM levels of rudeness in my view. It's a fine line to tread!

Answer 2

The old posts are cycled down the list so I would have to say the most active post is the "hot button" as far as if you want people to see your answer that would be the place to go. Havering a bunch of links to your answer is not too bad an idea but make sure your answer brings new light to the questions (in any form) better than any previous answer and explain the subtle improvements you have highlighted in your answer.