 What was thought to be used as an indication to settle the confusion between the crew and the two humans in moon-town?
As though there were but one city, if that is its form. But this might be so varied or so unfamiliar that often both the machine and the designer of it were puzzled as to how to read the results. It was for this reason that Glaser used that model no more, but built others more amenable. The Little Probe hovered stationary in the light and the moon-town came up under the dawn. "Not a building, not two sticks or stones placed together. And those two ... why, they could well be Earth-people. There was a man and a woman, and they were clothed either in very bright garments or in no garments at all, but only in a very bright light.
 A game of checkers
 An inquisition about knowledge  A game of checkers  A contest of preternatural intellect  A physical test