Random Card Generator: PSI Test #3

If you are as big a fan of the movie Ghostbusters as I am then I know you will recognize these cards. They are called Zener Cards.

Zener cards are cards used to conduct experiments for extra-sensory perception (ESP), most often clairvoyance. Perceptual psychologist Karl Zener designed the cards in the early 1930s for experiments conducted with his colleague, parapsychologist J. B. Rhine.

Although Zener cards are usually used to test for clairvoyance, they may also be used to test for telepathy, in which case one subject will draw a card and attempt to mentally project the image on it to the mind of another subject. Here, the statistical tendency of the receiver to report a specific design must be taken into account — for example, they might tend to report receiving an image of a square more than other images — so the cards are completely random.

Since the five symbols are completely random, guesses by a non-psychic in a controlled test would on average result in 1 / 5 × 25 = 5 correct guesses per deck and a success rate of 20%.