Are men or women more likely to feel rushed? Are Americans feeling more rushed over time? Do men and women differ with regard to career aspirations? Is AZT an effective drug for preventing mother-to-child transmission of AIDS? Did the Back to Sleep promotional campaign help convince more parents to put babies on their backs to sleep? You will investigate these and other questions in this topic as you discover statistical methods for exploring relationships between categorical variables.
After you have collected data, a useful first step in analyzing the data is to summarize their distribution. This often involves creating both graphical displays and numerical summaries. In this unit, you will examine strategies and methods for summarizing data, starting with categorical variables. In this topic, you will learn to construct and analyze two-way tables that allow you to compare the data for categorical variables. Although the mathematical operations you will perform are no more complicated than adding and calculating proportions, you will acquire some powerful analytical tools for addressing interesting research questions. You will also find that the lessons you learned in the first unit about collecting data and the types of conclusions you can draw from a study continue to apply.