NUMBAT OER - Open Educational Resources

A scatter plot is the appropriate graph to show the relationship between two variables. In the case of a regression, the independent variable is on the horizontal axis, and the dependent variable is on the vertical axis.

Species richness scatter graph
Figure 1. Example of a scatter plot, in this case indicating the relationship between species richness and wildlife reseve area. The right hand panel shows the same plot with the linear model overlaid
(Source: Brashares, JS, Arcese, P and Sam, MK (2001) Human geography and reserve size predict wildlife extinction in West Africa. Proceedings of the Royal Society of London, Series B 268, 2473-8.)

Since linear regression is a parametric test, you may need plot histograms of each variable to check whether they are normally distributed.

Example histogram
Figure 2. Example histogram, in this case showing the distribution of sperm length. The data are approximately normally distributed