How to anticipate moderating effects

[aleksaah]

Hi.

I have a large dataset and based on some or all of the variables in that dataset, I want to create a regression model using SPSS. However, it was mentioned that "some variables might also moderate the effects of other variables". How can I check for moderating effects between variables? I'm not sure if I'm asking the question 100% correct, but I hope some smart brains out there know what I mean

Best regards

[noetsi]

The best way to do this is in SEM which allows the role of moderating variables to be specifically modeled. But that is much more complex than regression and SPSS won't do it. In regression you want to have ideally a theory of which variables will moderate (perhaps by consulting the literature on your topic). Alternately you can look for the impact on the variables influenced by the moderating variables when you remove the moderators. There are signs to look for, such as dramatic changes (for instance a variable's sign reversing when the moderator is removed).

It is, in OLS, as much an artform as a science.