Editing Interaction (statistics) (section)

===Example: Interaction of species and air temperature and their effect on body temperature===

Consider a study of the body temperature of different species at different air temperatures, in degrees Fahrenheit. The data are shown in the table below.

[[File:Body temperature species data 2.png|Body temperature species data]]

The interaction plot may use either the air temperature or the species as the x axis. The second factor is represented by lines on the interaction plot.

[[File:Interaction plot body temp.svg|interaction plot body temp]]

[[File:Interaction plot body temp 2.svg|interaction plot body temp 2]]

There is an interaction between the two factors (air temperature and species) in their effect on the response (body temperature), because the effect of the air temperature depends on the species. The interaction is indicated on the plot because the lines are not parallel.