Another maybe-negative use of this strategy, as conveyed to me by a famous professor:
If you give a technical talk and afterwards someone asks a question you don't know how to answer, instead answer a similar question you can answer. Then the audience will think you just misunderstood the question, rather than thinking that you didn't know the answer. This strategy won't work if the questioner is persistent, but usually they aren't.
> This strategy won't work if the questioner is persistent, but usually they aren't.
I think it may only seem to work to the person answering the question. Having sat in on many talks, it's often noticeable when a person answers a different question vs genuinely misunderstanding.
In astronomy, at least, I'd rather admit I didn't know the answer than try to fake it by answering a different question.