Test for continuous-by-class interaction

[issac]

Hi folks;

Am working with 9.3 version. I wonder what test is the best for testing possible interactions with one continuous variable and one class variable. Let's say, I have Length-Of-Stay as continuous and Race as class and would like to test whether the interaction is significant or not.

Thanks!

Issac

[art297]

It's late on a Friday, but I'm either missing something or you are looking for something that can't exist.  Isn't an interaction, by definition, differences in a dependent variable based on the levels of two or more independent variables.

If you just want to identify whether differences are significant, and your data meet the test's assumptions, couldn't you get what you want by simply using a one way anova?

Take a look at: http://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#statug_anova_sect00...

[PGStats · Accepted solution]

Search for "Homogeneity-of-slopes" in the documentation. One should do this test before any ANCOVA.

PG

[issac]

Thank Arthur and PG

I think the way to go is to ANCOVA since there is one class and one continuous variables and check for slope homogeneity as well.

Issac