I am using AMOS Graphics. My structural model is complicated with 6 exogenous variables of interest and a very long list of (exogenous) control variables. I would allow all these to covary. AMOS apparently requires that I specify each possible covariance as a double-headed arrow and in the graphical interface this becomes a mess. Is there an easier way to specify "all exogenous variables can covary"?
Hello Erik,
Yes, this is one of the limitations of using the graphical method to specify a model.
AMOS does allow you to specify a model using (visual basic) command language. Have a look at chapter 37 (and 38-39) in the user manual: https://www.csun.edu/itr/downloads/docs/IBM_SPSS_Amos_User_GuideV24.pdf
This approach can actually save you time later on, if you ever try similar models with different data sets.
Good luck with your work.
You can try this:
Select the variables to be covaried. From "Plugins", select "Draw Covariances" (or something similar).
It should automatically add double-headed arrows to the selected variables. I tested it and confirmed that it worked even if I selected five or six predictors. (I used AMOS 27.)