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:
“Salad is roughage and a French idea.”
—U.S. grandmother. As quoted in “Once a Tramp, Always ...,” by M.F.K. Fisher (1969)
“‘Tis very certain that each man carries in his eye the exact indication of his rank in the immense scale of men, and we are always learning to read it. A complete man should need no auxiliaries to his personal presence.”
—Ralph Waldo Emerson (1803–1882)
“Tried by a New England eye, or the more practical wisdom of modern times, they are the oracles of a race already in its dotage; but held up to the sky, which is the only impartial and incorruptible ordeal, they are of a piece with its depth and serenity, and I am assured that they will have a place and significance as long as there is a sky to test them by.”
—Henry David Thoreau (1817–1862)