Interaction-Test

[Peter.Stats]

Hi all,

I am conducting a study and I am struggling finding an appropriate test for my hypothesis.
Here is the setting:
I have two independent measures. A is a categorical variable (e.g. gender) and B is an interval variable (e.g., SAT-score). My dependent variable C is ordinal.
First I expect to find that gender has an influence on C. Second I expect that B has an influence on C. And third I expect that the influence of A on C is stronger the higher B is.
Can someone help me find an appropriate test. I would be very grateful.
Thank you!

 

[hlsmith]

Please define your sample size and provide more information about the DV.

 

[Peter.Stats]

My sample size is 360. 180 women and 180 men. My dependent variable is a Likert-type scale from -5 - 5 (consisting of only 1 item and thus ordinal).

 

[hlsmith]

What do the distribution of response to the DV look like? Are they centered, or a whole bunch right at 5?

 

[Peter.Stats]

The distribution centered, but not around 0, but around 3.

 

[hlsmith]

Not traditional practice yet, but I would fit a multiple quantile regression model. The process is just like linear regression, but you wont have to worry about that hideous DV. I haven't done one with a binary*continuous interaction, but it seems like it should be fine.

 

[Peter.Stats]

Do you think I could use an ordinal regression model?

 

[hlsmith]

You could, but if you think about the number of Obs, things will get fairly sparse. Meaning I believe with ordinal logistic reg you will be comparing multiple groups to a reference, plus the other main effect term and the interaction. So you would be comparing 1 to 5,..,1 to 2.