Coincidence

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A '''coincidence''' are a series of two or more chance events that appear to be related but really aren't. Many forms of [[superstition]] and [[pseudoscience]] have their origins in the misinterpretation of said events. The reason for this is a failure to apply [[Statistics|statistical]] thinking to real-life situations.
 
A '''coincidence''' are a series of two or more chance events that appear to be related but really aren't. Many forms of [[superstition]] and [[pseudoscience]] have their origins in the misinterpretation of said events. The reason for this is a failure to apply [[Statistics|statistical]] thinking to real-life situations.
  
For instance: A person dreams about an acquaintance or friend of theirs whom they have not seen for several years, and about whom they have not thought about for quite some time. The next day, they meet the acquaintance on the street or receive a phone call or email from him. To the untrained mind, this would appear to be so unlikely that it must be evidence of a sixth sense. However, [[Improbable things happen|improbability does not mean impossibility]]. Yes, it's a very unlikely event, but people get many tries for this sort of thing to happen. A person dreams thousands of times over the course of their lifetime, and [[Confirmation bias|they forget the vast majority of times when no similarity to an interesting event was present in the dream.]] They are struck by the one coincidence, but do not note all the other mundane dreams that had no relation to the events of the day. If you flip a coin thousands of times, you will eventually get some very improbable sequence of results, such as 10 tails or heads in a row (this is more or less the reasoning behind [[Littlewood's law of miracles]]).
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For instance: A person dreams about an acquaintance or friend of theirs whom they have not seen for several years, and about whom they have not thought about for quite some time. The next day, they meet the acquaintance on the street or receive a phone call or email from him. To the untrained mind, this would appear to be so unlikely that it must be evidence of a [[ESP|sixth sense]]. However, [[Improbable things happen|improbability does not mean impossibility]]. Yes, it's a very unlikely event, but people get many tries for this sort of thing to happen. A person dreams thousands of times over the course of their lifetime, and [[Confirmation bias|they forget the vast majority of times when no similarity to an interesting event was present in the dream.]] They are struck by the one coincidence, but do not note all the other mundane dreams that had no relation to the events of the day. If you flip a coin thousands of times, you will eventually get some very improbable sequence of results, such as 10 heads or tails in a row (this is more or less the reasoning behind [[Littlewood's law of miracles]]).
  
 
The principle of confirmation bias also applies to [[alternative medicine]]. A person who believes in alternative medicine may attribute any and all improvement to the particular herb or supplement they were taking at the time, and ignore all the times when they took a supplement and nothing happened.
 
The principle of confirmation bias also applies to [[alternative medicine]]. A person who believes in alternative medicine may attribute any and all improvement to the particular herb or supplement they were taking at the time, and ignore all the times when they took a supplement and nothing happened.

Revision as of 15:30, 25 November 2013

People are entirely too disbelieving of coincidence. They are far too ready to dismiss it and to build arcane structures of extremely rickety substance in order to avoid it. I, on the other hand, see coincidence everywhere as an inevitable consequence of the laws of probability, according to which having no unusual coincidence is far more unusual than any coincidence could possibly be.
Isaac Asimov[1]

A coincidence are a series of two or more chance events that appear to be related but really aren't. Many forms of superstition and pseudoscience have their origins in the misinterpretation of said events. The reason for this is a failure to apply statistical thinking to real-life situations.

For instance: A person dreams about an acquaintance or friend of theirs whom they have not seen for several years, and about whom they have not thought about for quite some time. The next day, they meet the acquaintance on the street or receive a phone call or email from him. To the untrained mind, this would appear to be so unlikely that it must be evidence of a sixth sense. However, improbability does not mean impossibility. Yes, it's a very unlikely event, but people get many tries for this sort of thing to happen. A person dreams thousands of times over the course of their lifetime, and they forget the vast majority of times when no similarity to an interesting event was present in the dream. They are struck by the one coincidence, but do not note all the other mundane dreams that had no relation to the events of the day. If you flip a coin thousands of times, you will eventually get some very improbable sequence of results, such as 10 heads or tails in a row (this is more or less the reasoning behind Littlewood's law of miracles).

The principle of confirmation bias also applies to alternative medicine. A person who believes in alternative medicine may attribute any and all improvement to the particular herb or supplement they were taking at the time, and ignore all the times when they took a supplement and nothing happened.

Anecdotal evidence is not acceptable proof for these reasons. Statistical studies are required, because they take into account all the events, not merely the ones that strike one as interesting.

See also

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