ABSTRACT
A key objective of public administration and nonprofit organization research is to provide the information needed to improve the quality of decisions made by managers and administrators. Researchers use four different types of measurement data: nominal, ordinal, interval, and ratio. Statisticians have produced different statistical tests to analyze each data type. Statistics are used for two main purposes: as descriptive statistics, they are used to summarize a larger set of numbers, called a data set; as inferential statistics, the measurements of a smaller group, a sample, are used for making assumptions about a larger group, the population or universe of interest. The term statistics can be used to refer to a body of mathematical tools and techniques invented for analyzing and giving meaning to sets of numbers. Statistics may be parametric or nonparametric. Parametric statistics require that certain assumptions be made of the host population, such as a normal distribution. With nonparametric statistics, no such assumptions need be made.
