The computer displays a screen containing 16 color graphics, as shown below

Spectator just thinks of one of the graphics. He is then shown four consecutive screens showing a number of the same graphics, and is simply asked whether his chosen graphic is among them. After the fourth answer, the computer shows him which graphic he selected, as shown here.

This is, of course, based on an old trick that uses binary math to determine the chosen graphic. But the program cleverly disguises this. If you repeat it, the graphics are all in different places, and the sequence of answers changes whether the spectator selects the same graphic, or the graphic in the same place as his previous choice! Delivered on CD its yours for only