The Distribution of a Variable

The distribution of a variable refers to how the different values of that variable are spread out across observations. This distribution gives us a sense of what the most common values are for a given variable and how much these values vary. It can also alert us to unusual patterns in the data. Intuitively, we think about distributions in our personal life any time we think about how we “measure” up relative to everyone else on something (income, number of Facebook friends, GRE scores, etc.). We want to know where we “fall” in the distribution of one of these variables.

In this chapter we will first learn graphical techniques that allow us to visualize what the distribution of a variable looks like. For quantitative variables we will then move on to calculate important summary statistics that measure the center and spread of a distribution.

Slides for this module can be found here.

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