Chapter 9: Descriptive Statistics

At this point, we need to consider the basics of data analysis in social scientific research in more detail. In this chapter, we focus on descriptive statistics—a set of techniques for summarizing and displaying the data from your sample. We look first at some of the most common techniques for describing single variables, followed by some of the most common techniques for describing statistical relationships between variables. We then look at how to present descriptive statistics in writing and also in the form of tables and graphs that would be appropriate for an American Psychological Association (APA)-style research report. We end with some practical advice for organizing and carrying out your analyses.

LEARNING OBJECTIVES

• Understand the characteristics of distributions, including shape, modality, and symmetry
• Understand the measures of central tendency and under what conditions each may be used
• Understand the measures of dispersion of a distribution of scores
• Be aware how Cohen’s d and Pearson’s r demonstrate relationships among variables
• Be aware of common guidelines for the presentation of data in text, including in parentheses, in a table, or in a figure
• Understand why descriptive statistics are essential to quantitative analysis