Introduction to Nonparametric Analysis

One-Sample Tests

Base SAS software provides two one-sample tests in the UNIVARIATE procedure: a sign test and the Wilcoxon signed rank test. Both tests are designed for situations where you want to make an inference about the location (median) of a population. For example, suppose you want to test whether the median resting pulse rate of marathon runners differs from a specified value.

By default, both of these tests examine the hypothesis that the median of the population from which the sample is drawn is equal to a specified value, which is zero by default. The Wilcoxon signed rank test requires that the distribution be symmetric; the sign test does not require this assumption. These tests can also be used for the case of two related samples; see the section Comparing Two Independent Samples for more information.

These two tests are automatically provided by the UNIVARIATE procedure. For details, formulas, and examples, see the chapter "The UNIVARIATE Procedure" in the Base SAS Procedures Guide.