Wilcoxon signed-rank test
The Wilcoxon signed-rank test procedure compares the distributions of paired variable sets. The procedure considers information about both the sign of the differences and the magnitude of the differences between pairs.
- Example
- In general, do families receive the asking price when they sell their homes? By applying the Wilcoxon signed-rank test to data for 10 homes, you might learn that seven families receive less than the asking price, one family receives more than the asking price, and two families receive the asking price.
- Statistics
- Mean, standard deviation, minimum, maximum, number of non-missing cases, and quartiles. Tests: Wilcoxon signed-rank. If Sampling and Testing is installed (available only on Windows operating systems), the marginal homogeneity test is also available.
Data considerations
- Data
- Use numeric variables that can be ordered.
- Assumptions
- Although no particular distributions are assumed for the two variables, the population distribution of the paired differences is assumed to be symmetric.
Obtaining a Wilcoxon signed-rank test
- From the menus choose:
- Click Select variables under the Dependent variables section, select one or more paired sets of variables, and then click OK.
- Optionally, expand the Additional settings menu and click Options to specify the confidence interval, significance level, case basis for analysis, and user-missing values settings.
- Click Run analysis.
This procedure pastes NPTESTS command syntax.