Intermediate graphs

This chapter covers

■Visualizing bivariate and multivariate relationships

■Working with scatter and line plots

■Understanding corrgrams

■Using mosaic and association plots

In chapter 6 (basic graphs), we considered a wide range of graph types for displaying the distribution of single categorical or continuous variables. Chapter 8 (regression) reviewed graphical methods that are useful when predicting a continuous outcome variable from a set of predictor variables. In chapter 9 (analysis of variance), we considered techniques that are particularly useful for visualizing how groups differ on a continuous outcome variable. In many ways, the current chapter is a continuation and extension of the topics covered so far.

In this chapter, we’ll focus on graphical methods for displaying relationships between two variables (bivariate relationships) and between many variables (multivariate relationships). For example:

■What’s the relationship between automobile mileage and car weight? Does it vary by the number of cylinders the car has?

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