| Message/Author |
|
|
|
|
Hello,
I am fitting a mediation model and get the following error.
WARNING: THE LATENT VARIABLE COVARIANCE MATRIX (PSI) IS NOT POSITIVE
DEFINITE. THIS COULD INDICATE A NEGATIVE VARIANCE/RESIDUAL VARIANCE FOR A
LATENT VARIABLE, A CORRELATION GREATER OR EQUAL TO ONE BETWEEN TWO LATENT
VARIABLES, OR A LINEAR DEPENDENCY AMONG MORE THAN TWO LATENT VARIABLES.
CHECK THE TECH4 OUTPUT FOR MORE INFORMATION.
PROBLEM INVOLVING VARIABLE c1.
THE STANDARD ERRORS OF THE MODEL PARAMETER ESTIMATES COULD NOT BE
COMPUTED. THE MODEL MAY NOT BE IDENTIFIED. CHECK YOUR MODEL.
PROBLEM INVOLVING THE FOLLOWING PARAMETER:
Parameter 99, c1 WITH c2
THE CONDITION NUMBER IS -0.645D-10.
Both c1 and c2 are independent variables (covariates). c1 is ordinal and c2 is binary. Both are declared categorical.
I checked the TECH4 output and found the following between c1 and c2:
ESTIMATED COVARIANCE MATRIX FOR THE LATENT VARIABLES: -0.401
ESTIMATED CORRELATION MATRIX FOR THE LATENT VARIABLES: -0.975
I examined the data and there is not any coding issues. Is there a way resolve the issue? |
|
|
|
|
As an update, I respecified the model and obtained the following in the TECH4 output between c1 and c2:
ESTIMATED COVARIANCE MATRIX FOR THE LATENT VARIABLES: -0.418
ESTIMATED CORRELATION MATRIX FOR THE LATENT VARIABLES: -1.028 |
|
|
|
|
| We need to see your output - please send to Support along with your license number. |
|
|
| Jenny posted on Monday, February 12, 2018 - 8:36 am
|
|
|
Hi Dr. Muthen,
I'm running a five-factor hierarchical CFA and received the not positive definite message involving one of the first order factors. I saw that it has a small negative residual variance (non-sig) and correlation with the second-order factor of greater than 1. I fixed the negative residual variance to 0 and the model ran fine but the correlation between this factor and the second-order factor is 1. What do you suggest in this instance?
Thanks very much! |
|
|
|
|
| That suggests that the second-order factor has a perfect indicator which is fine (although it may be a bit unrealistic and my also indicate some model mis-specification). |
|
|
| fred posted on Wednesday, February 13, 2019 - 5:46 am
|
|
|
Hi,
In a fairly straight forward CFA I am receiving the error message of PSI not being definite and a reference to TECH4 for a specific latent variable . When I check for a negative variances in this variable there is none, the correlations are also below 1, I have a hard time finding the problem with the variable which causes this error. Thanks for any suggestions. |
|
|
|
|
| Please send the output and your license number to support@statmodel.com. |
|
|
| Back to top |
