Fisher's Exact Test

Run an exact fixed-margin 2 by 2 count test with odds ratio, p-value, and support table.

Counts
Alternative

p-value

Enter counts

Fisher exact test, fixed margins.

Test details
MetricValue
Fixed-margin support
xTable probabilityIncluded
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P(X = x) = choose(n,x) choose(M-n,N-x) / choose(M,N) How?

How this is calculated

Fisher's exact test fixes the row and column margins, then sums hypergeometric table probabilities from that fixed-margin support. The two-sided p-value includes tables with probability no larger than the observed table probability.

Formula: P(X = x) = choose(n,x) choose(M-n,N-x) / choose(M,N)

Sources

  1. SciPy fisher_exact. SciPy. Retrieved .
  2. R fisher.test. R Documentation. Retrieved .

Method last reviewed