Tests Based on Ranks use the ranks of the data rather than the data itself to calculate statistics. Therefore the data must have at least an ordinal scale of measurement. If data are non-numeric but ordinal and ranked, these rank tests may be the most powerful tests available. Even numeric variables which meet the requirements of parametric tests, such as independent, randomly distributed normal variables, can be efficiently analyzed by these tests. These rank tests are valid for variables which are continuous, discrete, or a mixture of both.
Types of Rank tests supported by Teradata Warehouse Miner include:
- Mann-Whitney/Kruskal-Wallis
- Mann-Whitney/Kruskal-Wallis (Independent Tests)
- Wilcoxon Signed Rank
- Friedman