I was reading about the Consistent Histories interpretation, or Super Copenhagen as it is called(though I see more similarity to Everett) when the question of reality in such a scheme was addressed. The answer, I believe by Hartle, was along the lines of this: "The agreement among human observers about what is happening and has happened...this agreement is explained in quantum mechanics by the fact that the great majority of us are using various coarse grainings of a single set of histories consituting the quasiclassical realm." My question, which may reflect just an ignorance(I'm still just an undergrad) is if observers were using various coarse grainings in a set, wouldn't they be perceiving various histories instead of one which they can agree upon? I don't see how agreement emerges. Just a peculiarity I noticed that's been bothering me, thanks in advance for any responses showing where I go wrong.