In general, the answer to your question is "yes". In fact, I'd argue good answers should recognize and call attention to any incorrect concepts in a question. If we ignore the rhino in the china shop and only talk about how to fix the china it breaks, the china is going to keep breaking and we'll have to keep fixing it.
That being said, proving a negative is very difficult. There are certainly times when a question may seem silly or poorly founded or researched.
I recommend you start by commenting on the question to ascertain where they got the information that they have or why they believe what they're asking is possible/true. Asking someone to show their work is perfectly fine and, if they comply, it will make both the question and the answers better. It will also give you a better chance to show why their assumptions are incorrect.
Negative answers need as much if not more supporting documents when answered because you're both
- proving them wrong (so you need sources that say why their assumptions are incorrect)
- proving yourself correct (so you need sources that say why you are correct)
So, when you do answer, you need to:
Explain why their assumption is wrong. But don't forget to Be Nice!.
- Do they quote some discredited studies/biased sources?
- Do they make assumptions based on a myth/old wives' tale?
- Is there a language barrier issue?
There are many explanations for why someone bases their question on data that may be incorrect.
Then, explain your point of view and support it with good sources. Remember that, particularly on some sites, your point of view will always be wrong to some readers. I would say that this is particularly true on sites like Parenting where you can find sources that debate just about every topic with very few definitive "answers".
In the case of some of the more subjective sites, it may be good to add an extra layer of "Be Nice" by framing your answer in a way that is very patient and respectful of differing opinions... unless they're quoting movie stars as if they were doctors.
As an example, someone recently asked (on Movies.SE) why a character in a film would wait for a loud point in a song to shoot if they have a silencer. This question is based on the fallacy (movie trope) that "silencers" make gunshots nearly inaudible when, in reality, suppressors do not actually "silence" the sound of a gunshot.
There are a couple of ways to answer this question:
- Only give a real-world explanation explaining that suppressors don't actually silence guns.
- Only give an in-world explanation for why this would happen.
- Only give a storytelling reason for why this would happen.
- Give all of the above.
Doing option one is similar to what you're talking about. It's certainly true but it doesn't necessarily actually answer the question, so it might not really help the person asking. Option two or three could each be helpful and would certainly answer the question and would probably be fine on their own... but
Doing all three in a long answer explaining the reality of how suppressors work (including videos of what suppressed guns sound like) along with an explanation for why the character might make that choice and an explanation of how suspense works both answers the question and teaches the asker (and future readers) something they may not have known.
Now, for some extremely obvious errors, it's possible the question would get closed. As an example, on English Language Learners, if someone asks a question about a quote that includes a typo, the fact of the typo is explained in the comments on the question and the question usually gets closed. But I don't think this is what you're talking about.
One other thing to remember. You say in your question
One thing I keep running into on this site is that some questions are merely asked so that a persons opinion can be validated.
If this is actually the case, this may be a non-question and it may be appropriate to close it as such. From the Don't Ask Page:
- there is no actual problem to be solved: “I’m curious if other people feel like I do.”
- your question is just a rant in disguise: “______ sucks, am I right?”