Skip to main content

Probability Model

PROBABILITY MODEL

A probability model, also known as a stochastic model, is a mathematical formulation that incorporates an element of randomness. This contrasts with a deterministic model, in which reliable predictions are made on the basis of observed variables. The simplest probability model is the Gaussian, or normal, distribution, of which there are many examples in biology, medicine, and public health. Variations in height, weight, blood pressure, and attack rates in outbreaks of disease are examples of Gaussian distribution.

There is an element of randomness in the distribution of many disease states, although deterministic factors also play a part. Thus, it is possible to estimate riskssuch as the risk of cancer following exposure to a known carcinogen but not to predict which individuals among the members of a high-risk group will develop cancer, or when. Many stochastic models display variation only within a relatively narrow range, however, so prediction, and therefore planning, is feasible within these limits.

John M. Last

(see also: Risk Assessment, Risk Management; Statistics for Public Health )

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Probability Model." Encyclopedia of Public Health. . Encyclopedia.com. 20 Aug. 2018 <http://www.encyclopedia.com>.

"Probability Model." Encyclopedia of Public Health. . Encyclopedia.com. (August 20, 2018). http://www.encyclopedia.com/education/encyclopedias-almanacs-transcripts-and-maps/probability-model

"Probability Model." Encyclopedia of Public Health. . Retrieved August 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/education/encyclopedias-almanacs-transcripts-and-maps/probability-model

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.