Interactions:

IVs = continuous & continuousIVs = continuous & categorical

What we already know…

Interactions: IVs = categorical & categorical

Interactions (continuous)

Interactions (continuous)

Can be done in SPSS with some tweaking:

Center the variables (X minus mean) Create interaction term (multiple them together) Put all three variables into “regression”

• V1 centered• V2 centered• V3 = new interaction “variable”

Multiple Regression

Graphs

You can tweak SPSS some more to create “graphs” of “+1SD” and “-1SD” but very tedious.

I would recommend this software:

http://www.danielsoper.com/Interaction/default.aspx

Costs $5. Super easy. Gives both “output” and “graphs”. I’ll show you how to use it when you want to run interactions on your data