This guide illustrates how to perform a variety of nonparametric tests. For information on nonparametric correlations and measures of association, see the page Nonparametric Correlations.
One-Sample Nonparametric Tests
- From an open JMP data table, select Analyze > Distribution.
- Select one or more continuous variables from Select Columns, click Y, Columns, and click OK. The variable ‘Horsepower’ was used in this example.
- From the Distributions report window, click on the red triangle for the variable and select Test Mean.
- Enter the hypothesized value under Specify Hypothesized Mean, check the Wilcoxon Signed Rank box, and click OK. The hypothesis being tested under the Wilcoxon Signed Rank test is: H0: Median = 140 vs. HA: Median ≠ 140
The following results for both the one-sample t-Test and the Signed-Rank are provided.
- The test statistics (the t-Test and Signed-Rank).
- P-values for both one- and two-tailed tests. The p-value for the two-tailed test is next to Prob > |t|.
Two-Sample and Oneway Nonparametric Tests
- Select Analyze > Fit Y by X.
- Select a continuous variable and click Y, Response, and select a categorical variable and click X, Factor, then click OK. The Oneway Analysis output window will display.
- Under the red triangle, select Nonparametric > Wilcoxon Test / Kruskal-Wallis Test to perform the analysis adding results to the report.
- If the categorical variable has only two levels, both the Normal Approximation and ChiSquare Approximation test statistics and corresponding p-values with be shown.
- If the variable has three or more levels, only the ChiSquare Approximation will be performed.
Note: the Wilcoxon / Kruskal-Wallis Rank Sum Test is sometimes called the Mann-Whitney Test.
Visit Basic Analysis > Distributions > Options for Continuous Variables > Test Mean, Basic Analysis > Oneway Analysis > The Oneway Platform Options, Basic Analysis > Oneway Analysis > Oneway Analysis Reports to learn more.