SUMMARY

Nonparametric statistics are a group of techniques that can be used for statistical analysis when the data are less than interval in measurement or when assumptions about population parameters, such as shape of the distribution, cannot be met. Nonparametric tests offer several advantages. Sometimes the nonparametric test is the only technique available, with no parametric alternative. Nonparametric tests can be used to analyze nominal- or ordinal-level data. Computations from nonparametric tests are usually simpler than those used with parametric tests. Probability statements obtained from most nonparametric tests are exact probabilities. Nonparametric techniques also have some disadvantages. They are wasteful of data whenever a parametric....