Paul Silvia posted on Tuesday, February 17, 2009 - 12:18 am
I've been reading Cheung's work on meta-analytic SEM, which pools correlation matrices via multiple-group analysis.
Will Mplus output such a pooled matrix, given summary correlation data?
(To tinker, I used summary data in correlation matrix form for 3 groups (same variables, no missing data) using NGROUPS and NOBSERVATIONS. The SAMPSTAT and TECH1-4 output reports separately for each group, but not for the combined sample.)
I can't think of any way to do this in Mplus. I'm assuming the pooled correlation matrix is the average of the three correlation matrices.
Paul Silvia posted on Tuesday, February 17, 2009 - 3:43 pm
Yup, it's just the average of the matrices. It sounds like it's time for the old-school approach: pen, paper, and calculator. Paul
Mike Cheung posted on Saturday, March 28, 2009 - 8:48 am
Mplus can be used to pool correlation matrices. The following is the sample Mplus code: TITLE: Pooling correlation matrices
DATA: FILE = test.cov; NGROUPS=2; TYPE IS COVARIANCE; ! Pretend correlation matrices as covariance matrices ! See Cheung and Chan (2005) NOBSERVATIONS = 100 100; VARIABLE: NAMES ARE x1-x3; USEVAR ARE ALL; MODEL: latent1 BY x1*; ! Estimated standard deviations latent2 BY x2*; latent3 BY x3*; latent1@1; latent2@1; latent3@1; x1@0; ! No measurement errors x2@0; x3@0; latent1 WITH latent2* (1); latent1 WITH latent3* (2); latent2 WITH latent3* (3); MODEL g2: latent1 BY x1*; ! Estimated standard deviations latent2 BY x2*; latent3 BY x3*; latent1 WITH latent2* (1); ! Constrain correlation matrices latent1 WITH latent3* (2); latent2 WITH latent3* (3); OUTPUT: SAMPSTAT;
I am performing a meta-analytic SEM on a pooled correlation matrix with many missing cells. Is Mplus capable of taking in summary data (such as FULLCORR) with missing cells at all?
Here's my input code: DATA: FILE = MASEM2.csv; TYPE IS FULLCORR; NOBSERVATIONS = 45925; VARIABLE: NAMES ARE AGE1-AGE26; USEVARIABLES ARE AGE1-AGE26; ANALYSIS: TYPE = GENERAL; ESTIMATOR=ML;
If Mplus is not designed to handle summary data with missing cells, what would you recommend I do to handle the missing cells? Impute them with another software? If so, is there a software that you would recommend?