How to handle vague terms

Question

Lots of questions with

"Is xxx Harmful?" "How dangerous is xxx" "Will yyy hurt you"

These are hard to answer and harder to debate. "Harm" and "Danger" are very subjective terms. Specifically with health it's always a function of quantity anyhow. Almost nothing is universally bad, or universally good, regardless of quantity. There is no universal safe assumption across all products. Safety amounts vary in orders of magnitude.

How do we edit/react/respond to questions like these that are too vague to produce useful answers?

Answer 1

Often, the situation is well-defined enough so that you can still write a solid and informative answer even if the question uses many vague terms. Under those circumstances, just go answer.

An example of such a question would be Fabian's CFL question. It uses vague terms like "harmless" and "dangerous" but the situation is limited enough so that you can write a good answer covering the health risks in the situation he's describing.

If it's so vague it would take mindreading to guess what is asked, or if the question is so generic it could be split in several questions, ask the user to be more specific. If he or she complies, then all is good. If the users does nothing, vote to close the question as "not a real question":

not a real question: It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form.

A good example of a question that is simply unanswerable is “E Numbers” - harmful or not? It's so generic and unclear that it's impossible to tell where to start. The high number of answers represent that well.

Don't just edit the question, though. I think that'd be a misuse of the edit privilege.