Examining Relationships Between Pairs of Variables
overview 

Use these graphs to explore relationships between one or more pairs of variables. For example, you can assess:

·    The relationship between soil pH and the growth of plants

·    The relationships between the viscosity, age, and temperature of oil and acceleration and wear in race-car engines

Graph

Uses

Scatterplot

 

Use a scatterplot to assess the relationship between two variables. The values of the two variables serve as the x- and y-coordinates for plotting each observation.

Display options include fitted lowess and regression lines.

Matrix Plot

 

Use a matrix plot to assess the relationships among several pairs of variables at once. A matrix plot is an array of individual scatterplots.

Display options include fitted lowess and regression lines.

Bubble Plot

 

Use a bubble plot to explore the relationships among three variables on a single plot. Like a scatterplot, a bubble plot plots a y-variable versus an x-variable. However, the symbols (also called bubbles) on the bubble plot vary in size. The area of each bubble represents the value of a third variable.

Marginal Plot

 

Use a marginal plot to assess the distributions of two variables as well as the relationship between them. A marginal plot is a scatterplot with histograms, boxplots, or dotplots in the margins.