(Note that the immediate alternative is to pose questions with word or phrase answers, but those are harder to describe abstractly and harder to ensure that someone will answer with exactly the correct spelling and formatting.)
That's something I thought about, sometime ago. You have to phrase and spell the answers to that kind of stuff exactly right, or else it doesn't work, and you're stuck there, frustrated because you know you have the right answer.
Is there a way to make'em multiple-answer questions? Like, for example, if we asked "what are blue, green and red?" What if the answer is "colors", but someone from the UK comes in and types "colo
urs"? If we made said question a multiple-answer one, then we could put in both "colors" and "colours" as acceptable. (Again, this is merely an example.)