Mplus VERSION 8.8
MUTHEN & MUTHEN
04/19/2022 11:11 PM
INPUT INSTRUCTIONS
TITLE: this is an example of a two-group twin
model for categorical outcomes using parameter
constraints
DATA: FILE = ex5.22.dat;
VARIABLE: NAMES = u1 u2 g;
GROUPING = g(1=mz 2=dz);
CATEGORICAL = u1 u2;
MODEL: [u1$1-u2$1](1);
u1 WITH u2(covmz);
MODEL dz: u1 WITH u2(covdz);
MODEL CONSTRAINT:
NEW(a c e h);
covmz = a**2 + c**2;
covdz = 0.5*a**2 + c**2;
e = 1 - (a**2 + c**2);
h = a**2/1;
INPUT READING TERMINATED NORMALLY
this is an example of a two-group twin
model for categorical outcomes using parameter
constraints
SUMMARY OF ANALYSIS
Number of groups 2
Number of observations
Group MZ 1000
Group DZ 1000
Total sample size 2000
Number of dependent variables 2
Number of independent variables 0
Number of continuous latent variables 0
Observed dependent variables
Binary and ordered categorical (ordinal)
U1 U2
Variables with special functions
Grouping variable G
Estimator WLSMV
Maximum number of iterations 1000
Convergence criterion 0.500D-04
Maximum number of steepest descent iterations 20
Parameterization DELTA
Link PROBIT
Input data file(s)
ex5.22.dat
Input data format FREE
UNIVARIATE PROPORTIONS AND COUNTS FOR CATEGORICAL VARIABLES
Group MZ
U1
Category 1 0.502 502.000
Category 2 0.498 498.000
U2
Category 1 0.494 494.000
Category 2 0.506 506.000
Group DZ
U1
Category 1 0.504 504.000
Category 2 0.496 496.000
U2
Category 1 0.511 511.000
Category 2 0.489 489.000
THE MODEL ESTIMATION TERMINATED NORMALLY
MODEL FIT INFORMATION
Number of Free Parameters 3
Chi-Square Test of Model Fit
Value 0.905*
Degrees of Freedom 3
P-Value 0.8242
Chi-Square Contribution From Each Group
MZ 0.476
DZ 0.429
* The chi-square value for MLM, MLMV, MLR, ULSMV, WLSM and WLSMV cannot be used
for chi-square difference testing in the regular way. MLM, MLR and WLSM
chi-square difference testing is described on the Mplus website. MLMV, WLSMV,
and ULSMV difference testing is done using the DIFFTEST option.
RMSEA (Root Mean Square Error Of Approximation)
Estimate 0.000
90 Percent C.I. 0.000 0.032
Probability RMSEA <= .05 0.992
CFI/TLI
CFI 1.000
TLI 1.000
Chi-Square Test of Model Fit for the Baseline Model
Value 952.816
Degrees of Freedom 2
P-Value 0.0000
SRMR (Standardized Root Mean Square Residual)
Value 0.005
Optimum Function Value for Weighted Least-Squares Estimator
Value 0.14675240D-03
MODEL RESULTS
Two-Tailed
Estimate S.E. Est./S.E. P-Value
Group MZ
U1 WITH
U2 0.771 0.026 29.391 0.000
Thresholds
U1$1 0.007 0.024 0.292 0.770
U2$1 0.007 0.024 0.292 0.770
Group DZ
U1 WITH
U2 0.411 0.044 9.437 0.000
Thresholds
U1$1 0.007 0.024 0.292 0.770
U2$1 0.007 0.024 0.292 0.770
New/Additional Parameters
A 0.848 0.060 14.123 0.000
C 0.228 0.199 1.146 0.252
E 0.229 0.026 8.744 0.000
H 0.719 0.102 7.061 0.000
QUALITY OF NUMERICAL RESULTS
Condition Number for the Information Matrix 0.469E-02
(ratio of smallest to largest eigenvalue)
Beginning Time: 23:11:18
Ending Time: 23:11:19
Elapsed Time: 00:00:01
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