Article/Linkblog: Brown and Heathers: the GRIM test
tl;dr: A number of psychology papers report arithmetic means that are impossible given integer data.
''—that this piece we have now before us, which this worthy gentleman has in his hands, not only is no barber's basin, but is as far from being one as white is from black, and truth from falsehood; I say, moreover, that this, although it is a helmet, is not a complete helmet.''
''The Golden Helmet'' is a 32-page funny animal comic book adventure story written, drawn, and lettered by Carl Barks.
tl;dr: A number of psychology papers report arithmetic means that are impossible given integer data.