Non-Parametric Rank Tests

References .............................................................................................................................................. 289 Exercises ............................................................................................................................. 289

Empirical procedures, such as the permutation tests discussed in Chapter 12, can be regarded as

non-

parametric

because they do not use the parametric estimates that are required for the t, Z, and chi-square tests. In customary statistical usage, however, the name

non-parametric

is often reserved for a different set of procedures, discussed in this chapter, that use the

ranks

of the observed data rather than the original values. The procedures are often called

non-parametric

rank

tests

or simply

rank tests

.