I've noticed an interesting hierarchy in American English. The top of the hierarchy is "good" as in "this is good!" Second best is just a little less than good which is "not bad". If we don't want to come right and say something is a good idea, we say "that idea is not bad." In third place is "not good". If something seems to be going poorly but hasn't reached disastrous then we say "that's not good". Finally, we get just plain bad. When a systems administrator says "this is bad", you should probably got a donut and a hug because you are going to need the consolation. So there you have it, an interesting hiearchy in American English.

Good
Not Bad
Not Good
Bad

Your Friendly Philologist
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