Structural Equation Models with
Directly Observed Variables II
Identification
GPA
Example 7
A nonrecursive model
Felson and Bohrnstedt (1979) (Female subjects)
Over Identified Model
No. of Variances/Covariances = 21 No. of Parameters Estimated = 19
GPA
Example 7
A nonrecursive model
Felson and Bohrnstedt (1979) (Female subjects)
Over Identified Model
No. of Variances/Covariances = 21 No. of Parameters Estimated = 20
gpa
height
weight
rating
academic
attract
error1
error2
1 1
Over Ideridentified Model
Number of variances/covariances = 21 No. of parameters estimated =20
GPA
Example 7
A nonrecursive model
Felson and Bohrnstedt (1979) (Female subjects)
Just Identified Model
No. of Variances/Covariances = 21 No. of Parameters Estimated = 21
GPA
Example 7
A nonrecursive model
Felson and Bohrnstedt (1979) (Female subjects)
Just Identified Model
No. of Variances/Covariances = 21 No. of Parameters Estimated = 21
GPA
Example 7
A nonrecursive model
Felson and Bohrnstedt (1979) (Female subjects)
Under Identified Model
No. of Variances/Covariances = 21 No. of Parameters Estimated = 22
Covariances
Covariances among Observed
Variables
rowtype varname perform knowl value sat train
n 98 98 98 98 98
cov perform 0.022
cov knowl 0.017 0.053
cov value 0.024 0.028 0.121
cov sat train 0.004 0.004 -0.006 0.09
cov train 0.018 0.018 0.035 -0.006 0.094
Covariances among Exogenous
Variables
gpa
height
weight
rating
academic
attract
error1
error2
1 1
Underidentified Model
Number of variances/covariances = 21 No. of parameters estimated =22
Covariances among Measurement
Errors
anomia67 powles67 anomia71 powles71
educatio SEI
67
Example 6: Model C Exploratory analysis
GPA
Example 7
A nonrecursive model
Felson and Bohrnstedt (1979) (Female subjects)
Over Identified Model
No. of Variances/Covariances = 21 No. of Parameters Estimated = 20
DF = 1
Class Exercise
• Create a new model:
– From the menu choose File/New
• Specify the Data file:
– Choose File/Data Files
– Browse to the tutorial folder. The path is:
• C:\Program Files\Amos 6\Examples • In the Files of type list select SPSS • Select Fels_mal.sav
