Message/Author 

Paul Silvia posted on Tuesday, February 17, 2009  12:18 am



Hi: I've been reading Cheung's work on metaanalytic SEM, which pools correlation matrices via multiplegroup 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 TECH14 output reports separately for each group, but not for the combined sample.) Thanks, Paul 


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 oldschool approach: pen, paper, and calculator. Paul 

Mike Cheung posted on Saturday, March 28, 2009  8:48 am



Hi Paul, 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 x1x3; 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; Regards, Mike 


Hi.... I have also been reading Cheung's work on metaanalytic SEM. Might I ask if I can use the raw data to "create" a pooled correlation matrices or covariance matrices? And if I have obtained a pooled correlation matrices or covariance matrices in Mplus, how I can use it to do a CFA? Thank you very much for your kind attention. Kit 


See the SAMPLE option in SAVEDATA. You can use this to create a pooledwithin covariance matrix. See Example 13.1 for how to use a covariance matrix as data. For a pooledwithin covariance matrix the sample size is the number of observations minus the number of clusters. 


Thank you very much for your reply. 


Dear Drs. Muthen & Muthen, I am performing a metaanalytic 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 AGE1AGE26; USEVARIABLES ARE AGE1AGE26; 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? Thank you very much! Best regards, Ke Anne Zhang 


No, Mplus cannot handle summary data with missing cells. I don't know of a program that can. 

Back to top 