I tried to find a pre-existing question for this but couldn't find one... if there is one, consider this ironic.

I was wondering if there is a guideline / strategy / recommendation of how to deal with multiple similar / partially overlapping questions or answers. I know the official stance is that the repeated questions have value in their different wording to make answers more findable, but the flip-side is that there often doesn't end up being one place that has the full answer on a given topic.

Now it would seem logical that merging such questions and/or answers into a more complete whole and then referring the less complete versions to the full explanation (maybe there even needs to be an canonical-answer tag for such Q/As?).

But are there actually any guidelines on this? Create a new question and answer to hold the (new) complete answer? Or will this result in people offering up more incomplete answers while the new question is being copy-edited? ... Pick one of the existing Q/As and turn it into a complete version? How to pick which one to start from?

This isn't going to be necessary with every topic, but over the last few weeks I have seen at least half a dozen variants of the "I have a generic type in .NET, but I want to bind its type argument at run time... why doesn't it take a Type parameter?".

This Stack Overflow blog post kinda addresses the duplicates issue: https://blog.stackoverflow.com/2009/04/handling-duplicate-questions/, but does not exactly cover the case I am discussing here.

Basically, what I am discussing here is multiple questions that fall in the 'Borderline duplicates' category, where the recommendation is to leave them all standing, because it increases the surface area for different wordings when searching for a question.

What I'm trying to address here is when borderline duplicates discuss the same topic without being the same question, and where as a result, none of the individual answers treat the topic in-depth enough for any of them to be the 'canonical' resource on the topic.

What I'm trying to suggest here is a mechanism for consolidating this knowledge and referring the original questions to this one resource to avoid users being faced with half a dozen related questions that discuss a topic, maybe none of which exactly cover their question, or maybe they give up after trying a few of the questions, when the next one possibly could have answered them.

  • 3
    Plus the perennial ones about why 10.0 / 2.0 <> 5.0 (or 4.999999) and what's with this syntax - "if (5 == c)..."
    – ChrisF Mod
    Commented Jun 9, 2009 at 15:16
  • 1
    very difficult problem, touched on in the blog recently blog.stackoverflow.com/2010/11/… Commented Nov 23, 2010 at 9:34

1 Answer 1


It looks like nobody is willing to stick out their necks on this one, so let me give my suggestion to start the discussion.

When to merge questions

  • There are a number of pre-existing questions that all deal with the same topic
  • The topics are all closely related and narrow (no big essays covering a whole technology)

No premature optimization: merging is frowned upon if there are not at least three questions already dealing with the topic. Let the actual questions decide when in-depth treatment is warranted.

Process for merging

  • Write a new CW question that covers all the details from the questions that are being merged
  • Pick a title that indicates the topic covered, do not make the title a question
  • Tag the question at least with 'canonical-answer'
  • Write an answer that includes at least the salient details from the accepted answers of the merged questions, but pad this answer out as needed to provide clear and total coverage of the topic
  • In the original unmerged questions, add a link at the top, formatted as: 'Canonical answer: <link to question>'

The use of the new 'canonical-answer' tag will make sure that those who want to make sure this mechanism meets minimum quality criteria can easily find all such merged questions and make sure the answers are as polished and complete as they can be.

Making a new question/answer and linking from the merged questions ensures that the impact on existing questions is minimal while still providing full details to anyone who happens to find one of the original questions through a search.

  • Maybe the question title even needs to start with 'Authoritative:' as well, so that when looking at a question on a topic that may not yet have a link to the authoritative answer, it will stand out in the 'Related questions' section as a good one to try next (and hopefully cross-link!)
    – jerryjvl
    Commented Jun 10, 2009 at 2:06
  • canonical sounds better than authoritative; and it's more accepted lingo. Commented Jun 11, 2009 at 19:35
  • Agreed... wasn't entirely happy with the term myself, looks a lot better now.
    – jerryjvl
    Commented Jun 12, 2009 at 2:29
  • Actually, I'll make it 'canonical-answer', since 'canonical' already is in use as a more general term.
    – jerryjvl
    Commented Jun 12, 2009 at 2:32
  • Added a concrete example to make the idea clearer... linked a limited number of articles for a flavour of that side of things, but didn't want to go all-out until there is some more feedback.
    – jerryjvl
    Commented Jun 12, 2009 at 14:32
  • Unfortunately, it's no longer possible to mark your own question as a community wiki post.
    – Stevoisiak
    Commented May 16, 2017 at 22:56

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