Residual variances
Message/Author
 steve posted on Friday, May 21, 2010 - 4:20 pm
Dear Linda and Bengt,

I would like to consider residual variances in addition to significance levels and size of factor loadings for judging the quality of my factor indicators. Does this make sense and would you recommend a cutoff value for the residuals?

Thanks a lot
 Linda K. Muthen posted on Saturday, May 22, 2010 - 7:44 am
Rather than residual variances, I would look at reliability of the factor indicators and the factor score determinacy which tells you how well the items measure the factors.
 steve posted on Saturday, May 22, 2010 - 10:12 am
Thanks Linda! I guess item reliability would be the variance explained by a factor?
 Linda K. Muthen posted on Saturday, May 22, 2010 - 4:00 pm
Yes.
 Chun-Yi Lee posted on Monday, April 23, 2012 - 11:56 pm
Dear Dr. Muthen,

I have tried conducting path analysis using Mplus.
However, it is strange that "Est./S.E." for the residual variances are all the same.
The output is as follows.
--------------------------------------------------------------
Residual Variances Estimates S.E. Est./S.E.
x1 9.298 0.299 31.081
x2 13.629 0.439 31.081
x3 2.699 0.087 31.081
x4 0.057 0.002 31.081
y1 24.355 0.784 31.081
y2 11.421 0.367 31.081
---------------------------------------------------------------

I would like to ask some questions.
Q1: Is there any upper bound for "Est./S.E."?
Yet, it is still strange since 13.629 / 0.439 = 31.046 < 31.081?
Q2: I was wondering why "Est./S.E." is not equal to Estimates divided by S.E.?

Thank you so much for your time.
 Linda K. Muthen posted on Tuesday, April 24, 2012 - 6:07 am
1. No.
 JuliaSchmid posted on Tuesday, January 31, 2017 - 8:21 am
Dear Linda and Bengt,

I would like to run a ESEM.Following error Message occurred: "THE RESIDUAL COVARIANCE MATRIX (THETA) IS NOT POSITIVE DEFINITE... PROBLEM INVOLVING VARIABLE KON4"

The item kon4 has a big residual variance (STDY: 999.000)

Do you have any suggestion, how I can handle this problem?

Thank you!
Julia
 Linda K. Muthen posted on Tuesday, January 31, 2017 - 12:12 pm
If Stdy is 999, it sounds like kon4 has a negative residual variance. 999 is printed when a value cannot be computed. A negative residual variance makes the results inadmissible. For further help, send the output and your license number to support@statmodel.com.