Organization of Data

Abstract

A statistical data set consists of a collection of values of one or more variables. The variables can be either numerical or categorical. Numerical variables are further classified as discrete or continuous. These distinctions determine the statistical approaches that are most appropriate for the data. For example, Section 2.1 describes methods for summarizing categorical data, and Section 2.2 pertains to discrete and continuous numerical variables. Examples of data include:

• a list of crime rates for large cities across the US;

• a set of weights of individuals attending a weight loss program;

• the numbers of errors made by cashiers on an 8-hour shift;

• the genders of individuals purchasing tickets to a concert; and

• a list of occupations of a sample of fathers and their sons.