Published on *OpenMx* (http://openmx.psyc.virginia.edu)

By *Niels*

Created *04/25/2010 - 16:46*

Sun, 04/25/2010 - 16:46 — Niels [1]

April 25, 2010

Hello to all,

I am very much new to OpenMx and still treading water over here. Specifically, I am having trouble fitting a multiple group CFA model to test various measurement invariance hypotheses. My main difficulty is that I cannot figure out how to specify my model so that the objective functions are combined across groups. I would be very grateful if someone could provide a very short script to fit a 2-group CFA model in RAM notation. Say, a 1-factor, three indicator model. No need to set equality constraints across groups -- I can handle that part. I just cannot figure out how to combine the objective functions with Ram specification. Any and all help very much appreciated. I am trying to move all of my class materials over the OpenMx.

Best, Niels

Niels Waller, Professor

Director of Quantitative/Psychometric Methods

Department of Psychology

N218 Elliott Hall

University of Minnesota

75 East River Road

Minneapolis Minnesota 55455

Phone: (612) 626-8729

Email: nwaller@umn.edu [2]

Homepage: http://www.psych.umn.edu/faculty/waller/ [3]

**Links:**

[1] http://openmx.psyc.virginia.edu/users/niels

[2] mailto:nwaller@umn.edu

[3] http://www.psych.umn.edu/faculty/waller/

[4] http://openmx.psyc.virginia.edu/thread/1367

[5] http://openmx.psyc.virginia.edu/thread/1318

[6] http://openmx.psyc.virginia.edu/forums/openmx-help/openmx-structural-equation-modeling