Design
Originally, tests for ESP were conducted using a standard deck of playing cards. However, there are many confounding variables involved with this methodology. When this methodology is used, a participant is only credited a correct prediction for guessing both the number and suit of the card. This means that the chance of correctly guessing a card is greatly reduced, and there is a lot of ambiguity involved with statistical analysis. Another problem with using playing cards is that many people will have a preference for a particular card, number or suit (Irwin 1999) and will constantly suggest that as their prediction for the next card that will appear. This led to the development of a set of cards known as Zener cards, invented by Karl Zener.
There are just five different Zener cards: a hollow circle (one curve), a Greek cross (two lines), three vertical wavy lines (or "waves"), a hollow square (four lines), and a hollow five-pointed star. There are 25 cards in a pack, five of each design.
When Zener cards were first used, they were made out of a fairly thin translucent white paper. Several subjects or groups of subjects scored very highly until it was discovered that they had often been able to see the symbols through the backs of the cards. A redesign made it impossible to see the designs through the cards under any conditions. A subsequent deck featured an illustration of a building at Duke University on its reverse side, but the use of a non-symmetric reverse design allowed the deck to be exploited as a one-way deck.
Read more about this topic: Zener Cards
Famous quotes containing the word design:
“The reason American cars don’t sell anymore is that they have forgotten how to design the American Dream. What does it matter if you buy a car today or six months from now, because cars are not beautiful. That’s why the American auto industry is in trouble: no design, no desire.”
—Karl Lagerfeld (b. 1938)
“Humility is often only the putting on of a submissiveness by which men hope to bring other people to submit to them; it is a more calculated sort of pride, which debases itself with a design of being exalted; and though this vice transform itself into a thousand several shapes, yet the disguise is never more effectual nor more capable of deceiving the world than when concealed under a form of humility.”
—François, Duc De La Rochefoucauld (1613–1680)
“What but design of darkness to appall?—
If design govern in a thing so small.”
—Robert Frost (1874–1963)