[fabian2k]

The vast majority of duplicate closures use already answered questions as duplicates. So ideally that question should have answers that apply to the new question as well. In my observation this is usually the case, though the answer might be more generic.

I have also seen bad duplicate closures that weren't actually exact duplicates. But people talk like this is the only kind of duplicate closure that actually happens. I've no idea if the rate of bad duplicates is so much higher than I observed, or if people are missing that their question is actually answered in the duplicate.

[freedomben]

I was extremely active on SO and other SE sites in the late 00s and early 10s. In those days it wasn't too bad, many duplicates were actually duplicates. However that really did start shifting. This is anecdata of course, but even questions that linked to possibel "duplicates" and pre-expalined why it wasn't the same question were often just closed as duplicates of the exact question that was linked. This happened to me several times before I got fed up and moved on with my life.

SO was a really rewarding place to ask and answer questions in those early days. It really is a crying shame what they did to the community by empowering the worst of the community to be the bosses.

[fenomas]

> So ideally that question should have answers that apply to the new question as well.

The point is who decides. If you ask a question and I flag it as a dupe, I might think the answers on the other question apply to yours, but only you know whether they solved your problem or not.

> I've no idea if the rate of bad duplicates is so much higher than I observed,

Sure, and neither does SO! They didn't even measure it. They only looked at the signal "does somebody with points think these questions are similar", and discarded the signal of whether the new user got any value out of the site, and I think that's what did them in.

[zahlman]

> The point is who decides. If you ask a question and I flag it as a dupe, I might think the answers on the other question apply to yours, but only you know whether they solved your problem or not.

The site is not about solving your problem. The site is about answering your question.

By policy, whether a question is a duplicate depends on whether answers at the target answer the question that is actually present in the "question" post. The details required to adapt that Q&A to the originally motivating situation are irrelevant.

In fact, there doesn't need to be an originally motivating situation in order to ask a valid question.

In fact, you don't actually need to know an answer in order to ask a valid question. It is perfectly acceptable, and even encouraged, to ask a question you know how to answer already, and provide the answer. (But both question and answer must meet standards, which are independent of who is asking and who is answering.)

> Sure, and neither does SO! They didn't even measure it.

This fundamentally can't be measured. Especially not when the claim of "bad duplicate" usually comes from people who are demonstrably not interested in what the policy is.

[fenomas]

> The site is not about solving your problem. The site is about answering your question.

The point stands either way, reread my comment. When you ask a question on SO and somebody posts a regular answer, you the asker decide whether they've answered your question/solved your problem/Xed your Y/whatever else. Until you accept it as correct, SO assumes the posted answer did not X your Y.

In contrast when random people flag your question as a dupe, they the random people decide that the other question Xes your Y. If they misread your question, tough luck, SO assumes they are correct even though you're the only one who actually knows. That's the point I was making.

> This fundamentally can't be measured.

Again, reread my comments. If SO let other people suggest that an existing question Xes your Y, and gave you a button to accept their suggestion, then SO would know roughly how often dupe flags are correct.