# Law of Truly Large Numbers

Law of Truly Large Numbers

The Law of Truly Large Numbers, attributed to Persi Diaconis and Frederick Mosteller, states that with a sample size large enough, any outrageous thing is likely to happen. It seeks to debunk one element of supposed supernatural phenomenology.

Here is a simplified example of the law:

Assume that a given event happens with a likelihood of 0.1% in one occurrence. For it not to happen in a sample of 1000 occurrences would require a probability of 0.999 to the power of 1000, a probability of 36.8%. This means that this individually unlikely event has a probability of 63.2% of happening if 1000 chances are given. In other words, even given a highly unlikely event, the chance that it never happens, given enough time, is even less likely.

Because we never find it notable when the likely thing happens, we highlight unlikely events and notice them more.

In pseudoscience

The law comes up in pseudoscience and is sometimes called the Jeane Dixon effect (see also Postdiction). It holds that the more predictions a psychic makes, the better the odds that one of them will "hit." Thus, if one comes true, the psychic expects us to forget the vast majority which did not happen.

Humans can be susceptible to this fallacy. A similar manifestation can be found in gambling, where gamblers tend to remember their wins and forget their losses and thus hold an inflated view of their real winnings.

ee also

*Coincidence
*Large numbers
*Law of large numbers
*Law of small numbers
*Littlewood's law
*Miracle
*Psychic phenomena

External links

* [http://skepdic.com/lawofnumbers.html skepdic.com on the "Law of Truly Large Numbers"]
* [http://mathworld.wolfram.com/LawofTrulyLargeNumbers.html mathworld.wolfram.com on the "Law of Truly Large Numbers"]
* [http://www.quackwatch.org/04ConsumerEducation/coincidence.html on the "Law of Truly Large Numbers"]

Wikimedia Foundation. 2010.

### Look at other dictionaries:

• Littlewood's law — states that individuals can expect a miracle to happen to them at the rate of about one per month.The law was framed by Cambridge University Professor J. E. Littlewood, and published in a collection of his work, A Mathematician s Miscellany ; it… …   Wikipedia

• List of mathematics articles (L) — NOTOC L L (complexity) L BFGS L² cohomology L function L game L notation L system L theory L Analyse des Infiniment Petits pour l Intelligence des Lignes Courbes L Hôpital s rule L(R) La Géométrie Labeled graph Labelled enumeration theorem Lack… …   Wikipedia

• List of statistics topics — Please add any Wikipedia articles related to statistics that are not already on this list.The Related changes link in the margin of this page (below search) leads to a list of the most recent changes to the articles listed below. To see the most… …   Wikipedia

• Empirical statistical laws — An empirical statistical law or (in popular terminology) a law of statistics represents a type of behaviour that has been found across a number of datasets and, indeed, across a range of types of data sets. Many of these observances have been… …   Wikipedia

• United States antitrust law — is the body of laws that prohibits anti competitive behavior (monopoly) and unfair business practices. These competition laws make illegal certain practices deemed to hurt businesses or consumers or both, or generally to violate standards of… …   Wikipedia

• Precognition — Premonition redirects here. For other meanings, see Premonition (disambiguation). Part of a series of articles on the paranormal Main articles Afterlife · Astral projection · Aura · Clairvoyance  …   Wikipedia

• Precognitive dreams — are dreams that have been credited with foresight or precognition. It is a phenomenon that has fascinated and puzzled mankind for thousands of years. Precognition is typically defined as knowing or perceiving events before they actually occur.… …   Wikipedia

• Notable dreams throughout history — On several occasions throughout history dreams have been credited for causing very important events. This includes problem solving, decision making, and apparent Precognition while dreaming. This phenomena has been variously interpreted.Notable… …   Wikipedia

• List of dreams — On several occasions throughout history dreams have been credited for causing very important events. This includes problem solving, decision making, and apparent precognition while dreaming. These phenomena has been variously interpreted.… …   Wikipedia

• Ohm's law — This article is about the law related to electricity. For other uses, see Ohm s acoustic law. V, I, and R, the parameters of Ohm s law. Ohm s law states that the current through a conductor between two points is directly proportional to the… …   Wikipedia

### Share the article and excerpts

##### Direct link
Do a right-click on the link above
and select “Copy Link”