What is the measure of novelty? This seems like a useless thing to attempt to measure, and then to claim one group "beats" another in it.
I could use an RNG to slam together a bunch of rules and I can pretty much guarantee novelty. There, I did it. I "beat" a professional designer. Is the game worth playing?
Well, you could, but then you only would have generated something "new," probably without any sense - something bizarre. That's why the authors measure usefulness, too. Only if both - novelty and usefulness - come together, you create something really creative. There is a lot of research about this, especially in the field of psychology.
I could use an RNG to slam together a bunch of rules and I can pretty much guarantee novelty. There, I did it. I "beat" a professional designer. Is the game worth playing?