The CALIS Procedure |
Relationships among Estimation Criteria |
The five estimation functions, , , , , and , belong to the following two groups:
The functions , , and take into account all elements of the symmetric residual matrix . This means that the off-diagonal residuals contribute twice to , as lower and as upper triangular elements.
The functions and take into account only the lower triangular elements of the symmetric residual matrix . This means that the off-diagonal residuals contribute to only once.
The function used in PROC CALIS differs from that used by the LISREL 7 program. Formula (1.25) of the LISREL 7 manual (Jöreskog and Sörbom 1988, p. 23) shows that LISREL groups the function in the first group by taking into account all elements of the symmetric residual matrix .
Relationship between DWLS and WLS:
PROC CALIS: The and estimation functions deliver the same results for the special case that the weight matrix used by WLS estimation is a diagonal matrix.
LISREL 7: This is not the case.
Relationship between DWLS and ULS:
LISREL 7: The and estimation functions deliver the same results for the special case that the diagonal weight matrix used by DWLS estimation is an identity matrix (contains only 1s).
PROC CALIS: To obtain the same results with and estimation, set the diagonal weight matrix used in DWLS estimation to
Because the reciprocal elements of the weight matrix are used in the goodness of fit function, the off-diagonal residuals are weighted by a factor of 2.
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