ABSTRACT
This chapter examines methods and techniques for summarizing and interpreting data. The discussion begins by examining numerical descriptive measures. These measures, commonly known as point estimators, enable inferences about a population by estimating the value of an unknown population parameter using a single value (or point). This chapter also overviews graphical representations of data. Relative to graphical methods, numerical methods provide precise and objectively determined values that can easily be manipulated, interpreted, and compared. They permit a more careful analysis of the data than more general impressions conveyed by graphical summaries. This is important when the data represent a sample from which inferences must be made concerning the entire population.
