Zener cards
a standardized set of stimulus materials, similar to a deck of playing cards, designed for use in experiments on extrasensory perception (ESP) and other parapsychological phenomena. The set consists of 25 cards, each of which bears one of five printed symbols (star, wavy lines, cross, circle, or square), with five cards in each category. In a typical test of telepathy, the cards are shuffled (usually mechanically) and a designated sender turns the cards over one at a time to inspect the symbol while a receiver attempts to guess the symbol by reading the thoughts of the sender. In an experiment on clairvoyance, the receiver might attempt to identify the order of the shuffled deck without any inspection of cards by the sender (see screen touch matching). In an experiment on psychokinesis, the participant would attempt to control the outcome of the shuffle directly. Also called ESP cards; Rhine
cards. See also basic technique; down through; ESP forced-choice test; general extrasensory perception; up through. [named in honor of Karl E. Zener (1903–1964), U.S. perceptual psychologist who designed the symbols, by his colleague Joseph B. Rhine, who devised the deck]