User Guide

121
Covariance Structures
Factor Analytic: First-Order. This
covariance structure has
heterogenous variances that are
composed of a term that is
heterogenous across elements
and a term that is homogenous
across elements. The covariance
between any two elements is the
square root of the product of
their heterogenous variance
terms.
Factor Analytic: First-Order,
Heterogenous.
This covariance
structure has heterogenous
variances that are composed of
two terms that are heterogenous
across elements. The covariance
between any two elements is the
square root of the product of the
first of their heterogenous
variance terms.
Huynh-Feldt. This is a “circular”
matrix in which the covariance
between any two elements is
equal to the average of their
variances minus a constant.
Neither the variances nor the
covariances are constant.
Scaled Identity. This structure has
constant variance. There is
assumed to be no correlation
between any elements.
l llllll
ll l ll ll
ll ll l ll
ll ll ll l
1
2
21 31 41
21 2
2
32 412
31 32 3
2
43
41 42 43 4
2
+
+
+
+
L
N
M
M
M
M
O
Q
P
P
P
P
d
d
d
d
l llllll
ll l ll ll
ll ll l ll
ll ll ll l
1
2
1213141
21 2
2
232 412
31 32 3
2
343
41 42 43 4
2
4
+
+
+
+
L
N
M
M
M
M
O
Q
P
P
P
P
d
d
d
d
s
ss
l
ss
l
ss
l
ss
ls
ss
l
ss
l
ss
l
ss
ls
ss
l
ss
l
ss
l
ss
ls
1
2
1
2
2
2
1
2
3
2
1
2
4
2
1
2
2
2
2
2
2
2
3
2
2
2
4
2
1
2
3
2
2
2
3
2
3
2
3
2
4
2
1
2
4
2
2
2
4
2
3
2
4
2
4
2
222
222
22 2
222
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
L
N
M
M
M
M
M
M
M
M
M
O
Q
P
P
P
P
P
P
P
P
P
s
2
1000
0100
0010
0001
L
N
M
M
M
M
O
Q
P
P
P
P