Usually if person 2 is giving advice, or ‘couching advice’ (indirectly suggesting), and the person 1 says it. I would take it as , I have not considered it, but now am and it seems workable and I am going over it. So here the person is now planning it out.
If person 1 is going over options on their own and says it, I would take it as it may be workable but maybe not the best option, and wants to find a better one. And here the person is searching for alternatives, and this one is plan B.
I’m British and I voted for a positive meaning. However it would be affected by tone:
“THAT’S not a bad iDEa…” - this suggests the speaker is pleasantly surprised and thinks the idea is a contender to be the solution.
“That’s not a BAD idea…” - this suggests that the speaker thinks the idea could perhaps be used as a last resort but you should carry on trying to come up with a much better solution.
Anything except “that’s a terrible idea” depending on the context and tone of voice.*
I’d think Brits would be slightly more likely to immediately claim the idea is not bad if they really “dislike it but don’t want to say so”, while I’d assume Americans would do that only if really pressed about an idea they consider sub-optimal. I’d assume everyone would likely point out the flaws of a horrible idea unless one were talking to one’s opinionated boss. Of course every individual can differ as to their level of outspokenness.
*Upon preview I agree with Stafford Cripps about the tones of voice I’d expect for an excellent or suboptimal idea, from an American as well.
To me it means “that’s an idea worth exploring. On paper it doesn’t sound bad.” But that’s what its close translations mean in Spanish, so I guess I’m coming more from Spanish than from any variant of English.
The phrase “Not bad,” depending on the context and on the way it’s said, can indicate moderately enthusiastic approval (“Hey, not bad!”), unenthusiastic or noncommittal approval (“What did you think of the movie?” “Eh, not bad.”), or moderate disapproval (as in the last line quoted above).
“Complimentary, cautiously good”. That is, it could well turn out to be a good idea and you are clever for thinking of it whether it works out or not.
Note that in my research activities working with others, we are generally welcoming and open to novel ideas. Even if some of them turn out later not to work. So telling someone who comes up with an approach to solving a problem that it’s not a bad idea is to recognize the idea as something that hopefully might work. Thanks for the input.
Now if it’s clear the idea will no doubt work, then more straightforward statements can be used. “Doc, you’re a genius!” “That’s what it says on the card.”
Inflection matters. It can change the meaning of a sentence by modifying how specific words are voiced. That’s how we often recognize sarcasm or even the difference between a statement and a question (as in Gambini v. State of Alabama: “I shot the clerk”).
But the phrase in question is so common in the US that it would take exaggerated intonations for people to interpret it as anything but “That’s a good idea”.
Anything other than it’s obviously a bad idea on first glance. That could mean it sounds amazing but I still want to thresh it out before I start doing back flips. It could mean it’s not particularly good but not so bad that it’s not worth looking at more fully.
Yeah. If anything, I would expect the American to parse it as slightly less positive - obviously they don’t; given the responses to this thread, “not a bad idea” has universal understanding - but it would fit in more with American English tending more towards positives that are obviously positive and British English having a lot of terms that sound like meh, but actually mean something positive. Like saying “not bad,” meaning actually “really rather good.”
Yeah, for most of these differences I’d have the British meaning in mind as a possibility or even implication if I heard it from an American co-worker. The two ones that say “do this optionally” in plain words but mean “do this mandatorily” in British did surprise me, but only due to the emphaticness of the command: in American office-speak, they don’t actually mean “do this optionally” either, but rather “it will reflect poorly upon you if you do not make your best effort to do these”, the actual degree of negative judgement varying depending on the boss, the work environment, and what other roadblocks were thrown your way in the meantime.
The most negative it can be is with an explicit or implied “but”: “That’s not a bad idea, but I have a better one”.
Absent that, it generally means somewhere between “That hadn’t occurred to me, but it might work; let’s explore the implications further and find out” and “That hadn’t occurred to me, but now that you mention it, that’s better than whatever I was thinking of; let’s do it”. It probably doesn’t mean “wow, that’s an amazing idea”, because that would probably have been expressed more strongly.