There have been a few questions recently that I voted to close as duplicates and also answered, because of the following:
I think the old question includes a valid answer to the new question, but I don't think it's trivial for the asker to identify how it answers their specific question even after we point them to the duplicate.
- I marked How do I negotiate an offer for PhD funding as a dup of Negotiating PhD funding. Roughly, the answer is the same (it can't hurt to ask if you are polite about it). But I think it might be onerous for the asker of the new question to identify the "nugget" that applies to his scenario, from among the advice that only applies to the old question.
- I marked Is IJCA a valid open access journal? as a dup of How do you judge the quality of a journal?. The answer to the former is basically a distillation of the latter; but I don't think the asker of the new question could have done that distillation himself.
How do we want to handle questions like these?
On the one hand, we don't want to spread answers to essentially the same question across duplicates.
On the other hand, we want users who come to this site and ask valid questions to feel like they got an answer. We don't want to tell them, "There's an answer, but you'll have to expend significant effort to dig through another question's answers to find the part you came for" (if they're even capable of doing so).
Also, sometimes there is an answer that is a better answer to the new question than any of the old answers; but the new answer wouldn't be a good answer to the old question.