Justice Ighodaro Odiase and Sunday Martins Ogbonmwan
Abstract
For a general class of problems, the permutation of observations is
the only possible method of truly constructing exact tests of
significance. The exact sampling distribution of a test statistic
for an experiment compiled by the permutation approach requires no
reference to a population distribution and therefore no requirement
that it should conform to a mathematically definable frequency
distribution. Algorithms for the exact permutation distribution of
correlation coefficients is presented and implemented. As an
illustrative example, critical values for Pearson's product moment
and Spearman's rank correlation coefficients are produced for
Charles Darwin's data on the heights of cross and self fertilized plants.
Keywords: Permutation test, Monte Carlo test, p-value, algorithm, paired observations, correlation.