ABSTRACT
Different statistical analysis procedures are required when dealing with either parametric or nonparametric statistics. The distinction between the two is based on the level of the measurement data. Nominal and ordinal measurements are nonparametric statistics; interval and ratio measurements are parametric statistics. The population data are assumed to have a normal distribution, for which two parameters—the mean and the standard deviation—must be assumed along with confidence intervals. Nonparametric statistics are statistics for which no parameter assumptions are necessary. For this reason, nonparametric statistics are referred to as distribution-free. This chapter describes the statistical tests used with nonparametric statistics.
