ABSTRACT
References .............................................................................................................................................. 240 Exercises ............................................................................................................................. 240
The procedures described in Chapter 12 are simple, direct, relatively easy to understand, and empirical. They use the evidence that was actually observed, and they require no excursions into a hypothetical world of parent populations and parameters. The tests can be used for stochastic contrasts of any two binary proportions, two means, or even, if desired, two medians. (In the last instance, the permuted samples would show the distribution of differences in medians, rather than means.)
Permutation tests, however, are not the customary methods used today for evaluating stochastic hypotheses. Instead, the conventional, traditional approaches rely on parametric procedures that are well known and long established. You may have never heard of the Fisher and Pitman-Welch tests before encountering them in Chapter 12, but your previous adventures in medical literature have surely brought a meeting somewhere with the two-group (or “two-sample”) Z and t tests.
