多组比较的问题么？方差是负的？

In AMOS, you would choose GLS or ULS by opening the View Menu and choosing 'Analysis Properties'. Then click the Estimation tab in the 'Analysis Properties' dialog box and check the radio button for either 'Generalized least squares' or 'Unweighted least squares'

http://www-01.ibm.com/support/docview.wss?uid=swg21476222