Learning about the different kinds of statistics

Learning about variables

Understanding the steps in statistical reasoning

Learning several uses for statistical reasoning

For many people, statistics means numbers—numerical facts, figures, or information. Statistics is about **data**. Data consists of information about statistical **variables**. There are two types of variables: **Quantitative variables** are variables that can be measured or described by values, such as height. Categorical variables have values that are categories, such as type of pet. The data for these variables are usually counts or frequencies of the numbers for each category.

Reports of industry production, baseball batting averages, government deficits, and so forth, are often called statistics. To be precise, these numbers are **descriptive statistics** because they are numerical data that describe phenomena. Descriptive statistics are as simple as the number of children in each family along a city block or as complex as the annual report released from the U.S. Department of the Treasury.