Duck test
From Wikipedia, the free encyclopedia
The duck test is a humorous term for a form of inductive reasoning. This is its usual expression:
If it looks like a duck, swims like a duck and quacks like a duck, then it probably is a duck.
The test implies that a person can identify an unknown subject by observing that subject's habitual characteristics. It is sometimes used to counter abstruse arguments that something is not what it appears to be.
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[edit] History
Indiana poet James Whitcomb Riley (1849–1916) may have coined the phrase when he wrote "when I see a bird that walks like a duck and swims like a duck and quacks like a duck, I call that bird a duck."[1][2]
The term was later popularized in the United States by Richard Cunningham Patterson Jr., United States ambassador to Guatemala during the Cold War in 1950, who used the phrase when he accused the Jacobo Arbenz Guzmán government of being Communist. Patterson explained his reasoning as follows:
Suppose you see a bird walking around in a farm yard. This bird has no label that says 'duck'. But the bird certainly looks like a duck. Also, he goes to the pond and you notice that he swims like a duck. Then he opens his beak and quacks like a duck. Well, by this time you have probably reached the conclusion that the bird is a duck, whether he's wearing a label or not."[3]
President Dwight D. Eisenhower authorized the United States Central Intelligence Agency to sponsor a coup of the Arbenz government to eliminate the supposed communist threat, ultimately causing a long civil war.[4][5]
Later references to the duck test include Richard Cardinal Cushing, who used the phrase in 1964 in reference to Fidel Castro.[6][7]
[edit] See also
- Duck typing
- Elephant test
- Identity of indiscernibles
- I know it when I see it
- Occam's razor
- To call a spade a spade
- Turing test
- Zebra (medical)
[edit] Notes
- ^ Davis, Robin S.. Who's Sitting on Your Nest Egg?. pp. 7. http://books.google.com/books?id=PEoti64PICIC&pg=PA7&dq=%22James+Whitcomb+Riley%22+%22when+I+see+a+bird+that+walks+like+a+duck+and+swims+%22&ei=JsHcSejCBoToM7SKge0O.
- ^ Heim, Michael. Exploring Indiana Highways. pp. 68. http://books.google.com/books?id=j7zds6xx7S0C&pg=PA68&dq=%22james+Riley%22+OR+%22James+Whitcomb+Riley%22+bird++duck&num=100&ei=BsPcSYWoHJCmNfG7tM4O.
- ^ Immerman, 1982, p. 102
- ^ Smith, Joseph; Simon Davis (2005). The A to Z of the Cold War. Scarecrow Press. ISBN 0810853841. http://www.google.com/books?id=Ch7SyPeBczMC&pg=PA161&dq=Arbenz+Dwight+D.+Eisenhower+Central+Intelligence+Agency&ei=F-3XSdXQN6b0ygThoK38Ag. p. 161.
- ^ Olson, James Stuart. Historical dictionary of the 1950s. pp. 116. http://www.google.com/books?id=eSBDF5_L3BgC&pg=PA116&dq=Guatemalan+Civil+War+Arbenz+Dwight+D.+Eisenhower+Central+Intelligence+Agency&as_brr=3&ei=te3XSYfEEp6-ywTylfjsAg.
- ^ Denver, Joseph (1965), Cushing of Boston: A Candid Portrait
- ^ Platt, Suzy. Respectfully quoted. Library of Congress, Library of Congress. Congressional Research Service. http://books.google.com/books?id=2Tu3bScwKKAC&pg=PT267&dq=%22when+I+see+a+bird+that+walks+like+a+duck+and+swims%22&ei=eL3cSYazBJKqMpG_6bMO. "Attributed to RICHARD CARDINAL CUSHING. Everett Dirksen and Herbert V. Prochnow, Quotation Finder, p. 55 (1971). Unverified."
[edit] References
- Christy, Howard Chandler (1982), The complete works of James Whitcomb Riley
- Denver, Joseph (1965), Cushing of Boston: A Candid Portrait
- Immerman, Richard H. (1982), written at Austin, Texas, The CIA in Guatemala: The Foreign Policy of Intervention, University of Texas Press
