I have drawn a model in AMOS Graphics in which several pairs of exogenous variables have no covariance arrows between them. When I click Analyze->Calculate Estimates, a pop-up dialog box appears with the following warning:
"AMOS will require the following pairs of variables to be uncorrelated". This statement is followed by a list of the pairs of exogenous variables with no connecting covariance arrows.
What does this warning mean?
The warning indicates that AMOS will assume that these variables are uncorrelated in forming the implied covariance matrix. The message is really just an alert that these assumptions are implied by the lack of covariance arrows between those variables. If that assumption is unrealistic, given the data, then they will be a source of model error. If you want to go forward with those assumptions, then just click the "Proceed with the analysis" button. If you did not intend to make those assumptions, then click the "Cancel the analysis" button and draw the covariance arrows where you think they