Example: Fisher's Exact Test
Fisher's exact test is exact because the sampling distribution (conditional on the marginals) is known exactly. Compare Pearson's chi-squared test, which (although it tests the same null) is not exact because the distribution of the test statistic is correct only asymptotically.
Read more about this topic: Exact Test
Famous quotes containing the words fisher, exact and/or test:
“A mother is not a person to lean on but a person to make leaning unnecessary.”
—Dorothy Canfield Fisher (20th century)
“The first moments of sleep are an image of death; a hazy torpor grips our thoughts and it becomes impossible for us to determine the exact instant when the “I,” under another form, continues the task of existence.”
—Gérard De Nerval (1808–1855)
“We do not quite say that the new is more valuable because it fits in; but its fitting in is a test of its value—a test, it is true, which can only be slowly and cautiously applied, for we are none of us infallible judges of conformity.”
—T.S. (Thomas Stearns)