Factor Scores for Random Slopes
Message/Author
 Michael J. Zyphur posted on Wednesday, April 12, 2006 - 7:42 pm
Hi Bengt or Linda,
I was wondering if either of you could tell me how Mplus computes factor scores if I request them for a random slope -- both a random slope used at the same level on which it was created and at a higher level of analysis.

Would the factor scores for a same-level random slope be the person-specific b-weights? Additionally, for the multilevel random-slope model (a within-groups slope made random at the between-groups level), would the groups' factor scores be b-weights?

In any event, do you think that traditional arguments levied against using factor scores as DVs (e.g., Skrondal & Laake, 2001) would be applicable to factor scores of random slopes?

Thanks for your time, and I hope everything is going well in Los Angeles!

cheers,
mike

Skrondal, A. and Laake, P. (2001). Regression among factor scores. Psychometrika 66, 563-575.
 Bengt O. Muthen posted on Thursday, April 13, 2006 - 10:57 am
In this context, factor scores are computed using the expected a posteriori method. I don't know what person-specific b-weights are. Yes, I think traditional arguments against factor scores hold here as well.
 Michael J. Zyphur posted on Thursday, April 13, 2006 - 3:24 pm
By person-specific b-weights I guess I just meant the derivative of the DV for each person given a fixed intercept. Would the expected value for each person/group along the random slope be such a derivative (i.e., the way to solve for Y given a fixed intercept and a known X value)?

mike
 Bengt O. Muthen posted on Thursday, April 13, 2006 - 7:04 pm
Not sure.
 Michael J. Zyphur posted on Friday, April 14, 2006 - 2:17 am
Hmm, let me try to desribe a different way: Is the expected a posteriori distribution of slopes a distribution of scores which solve for Y given a known value of X and a fixed intercept?