There's seems to be a fair bit of confusion about "great off topic" and "not a good example". In many cases I see questions that are way off topic being voted as great off-topic examples and questions that are slightly off-topic being voted "not a good example", when we really want to reverse to happen in order to define the boundaries of the site.
I think part of this is because people expect "great off-topic" to be the opposite of "great on-topic". This could be fixed at least in part by renaming "great off-topic example" to "slightly off-topic" and "not a good example" to "very off-topic". This would cause people to vote in a way that encourages defining the site's boundaries even if they don't understand which type is good or why. I think it would also help people asking questions understand what is desired for off-topic examples.
Since some people think having two options with off-topic in the name is a bad idea,
not a good example might also be renamed to
not helpful. I'm not convinced people would be unable to decide between
very off-topic though.