"Well, everyone else do feel free to follow along and try the math on that part.  Raise your hand when done."

"After all, a Lawful way of looking at the world shouldn't care whether you call your collected 'data' by the name of one experiment or two experiments.  You should always get exactly the same answer either way.  Though, to be sure, you might have occasional occasion to notice that different 'data-subsets' might have been collected under possibly different conditions."

"Well, everyone else do feel free to follow along and try the math on that part.  Raise your hand when done, practice accuracy before you practice speed."

"After all, a Lawful way of looking at the world shouldn't care whether you call your collected 'data' by the name of one experiment or two experiments.  You should always get exactly the same answer either way.  Though, to be sure, you might have occasional occasion to notice that different 'data-subsets' might have been collected under possibly different conditions."