Confidence interval

From Citizendium
Jump to navigation Jump to search
This article is a stub and thus not approved.
Main Article
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
This editable Main Article is under development and subject to a disclaimer.

The Confidence interval (CI) is a "range of values for a variable of interest, e.g., a rate, constructed so that this range has a specified probability of including the true value of the variable."[1]

In large samples, calculations for the CI for rates and proportions may be based on the normal distribution.[2][3]

The equation using the normal distribution is:[4]


For small samples, calculations should be made using the binomial distribution or the Poisson distribution.


  1. Anonymous (2023), Confidence interval (English). Medical Subject Headings. U.S. National Library of Medicine.
  2. Fleiss, Joseph L. (1973). Statistical methods for rates and proportions. New York: Wiley, 13. ISBN 0-471-26370-2. 
  3. Cochran, William Cox; Snedecor, George W. (1980). Statistical methods. Ames: Iowa State University Press, 118. ISBN 0-8138-1560-6. 
  4. Gardner MJ, Altman DG (March 1986). "Confidence intervals rather than P values: estimation rather than hypothesis testing". Br Med J (Clin Res Ed) 292 (6522): 746–50. PMID 3082422[e]