[R] Problems on testing moderating effect (or interactive effect).

[Guo Wei-Wei]

Hi everyone,

I want to do test on moderating effect. I have three factors, A, B,
and C. A has influence on B, and C moderating the influence.  The
relationship looks like this:

A -----> B
     ^
     |
    C

A, B, and C are all scale variables. I think I can test the moderating
effect by adding a interactive variable between A and C. But I'm not
sure how to do.

Is there a default way to do it in package sem?

I'm also thinking about create a interaction variable of A and C, but
I don't know how to it. A has n (n = 27) items and p (p = 288) cases
and C has m (m = 16) iterms and p (p = 288) cases.

Does anyone have any suggestion? Thanks in advance.