Extra Sensory Perception

The Zener cards are a deck of twenty-five cards, five of each symbol, used to conduct experiments for extrasensory perception (ESP) or clairvoyance. In a test for ESP, the experimenter picks up a card in a shuffled pack, observes the symbol, and records the answer of the person being tested, who would guess which of the five designs is on the card. The experimenter continues until all the cards in the pack are tested.

Source: https://en.wikipedia.org/wiki/Zener_cards