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| I have a large correlation matrix in excel that has multiple missing values. First off, can you please clarify what type of file I need to put this in for Mplus to read it (I've read different things- .txt. prn, etc.) Secondly, what- if anything- do I need to put in the cells that are the missing values for it to be read? Do I need to use "correlation" for type in this case and is an ML estimator the best/necessary option? |
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| Is it the correlation matrix that has missing correlations in it, or is it the raw data that has missing data for certain subjects on certain variables? |
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| It is the correlation matrix that has missing correlations in it. It is actually a correlation matrix of meta-analytically derived correlations wherein some correlations are not found in the literature. |
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| What kind of model are you fitting to this correlation matrix? |
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| I'm hoping to fit multiple models, both EFA and CFAs. More so CFA's where I want to compare various models with 1-4 latent factors (regarding psychopathy) and also to correlate those latent factors with other factors regarding the five factor model of personality. |
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| I don't see how this can be handled. Unless the missing correlation values are in a certain pattern so the matrix can be broken up into groups with fewer variables per group. |
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As it is, I don't see a way to break up the matrix into smaller groupings, and I am aiming to do models that necessarily require all of the information. To clarify- is it required that if one wants to use a correlation matrix as the sole input nothing can be missing?
I've read other studies with the same problem that state- "Missing correlations were estimated with composite
maximum likelihood (ML) methods. In this approach, an exploratory factor model
was first fit to the available correlations of the matrix; this
model was used to generate model-predicted correlations,
which were used as imputed values for the missing correlations
in the matrix."
Is this not possible with Mplus? |
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| I don't know about this composite ML approach, but if it is sound I would think there is a way to do it in Mplus. Please send me an article on it. |
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This is the article in which I found the above quote- Sharma, L., Markon, K. E., & Clark, L. A. (2014). Toward a theory of distinct types of 'impulsive' behaviors: A meta-analysis of self-report and behavioral measures. Psychological Bulletin, 140(2), 374-408. doi:10.1037/a0034418.
The authors talk only briefly about the technique on pg. 379 in the paragraph that begins "This methodology resulted in a 58X58 correlation matrix..." (I have emailed the corresponding author of this article to clarify what program they used as well). There are a few other resources they cite that I have either not yet had access to (Markon, 2011; Lindsay, 1988) or am having trouble following because of the complexity (Cudeck, 2000).
Continuing thanks for your responses. |
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| what is the Cudeck, 2000 ref? |
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| Cudek, R. (2000) An Estimate of the Covariance Between Variables Which are not Jointly Observed. Psychometrika, 65(4), 539-546. |
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| Will have a look at it. |
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