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Hello all,
I am trying to conduct a parameter based MetaSEM. My model includes several mediators which are in parallel, and one mediator in series with the others (Attached is the figure summarising the model).
I have tried to run the code, however, R is giving me the following error message:
Error in (function (x, n, standardized = TRUE, direct.effect = TRUE, run = TRUE) : length of 'dimnames' [1] not equal to array extent
Error: object 'indirect1' not found
I have attached the code I am currently using.
Based on the figure, have I respected the order of the variables in my code? Also, if I want to include a variable (covariate) predicting all the other variables, but I am not interested in its indirect effects, how can I do so?
I would highly appreciate the help.
Thank you in advance.
Regards,
Arin
Dear Arin,
The indirectEffect() in the metaSEM package can only be used for models with one predictor (x), one mediator (m), and one dependent variable (y). Your models are different from this one. Thus, it does not work.
If you want to conduct the parameter-based MASEM, you need to fit the model and estimate the indirect and direct effects manually. They can then be used in the multivariate meta-analysis. The second example in Cheung and Cheung (2016) illustrates how to do it. The R code is available at https://github.com/mikewlcheung/code-in-articles/blob/master/Cheung%20and%20Cheung%202016/REM.md
Cheung, M. W.-L., & Cheung, S. F. (2016). Random-effects models for meta-analytic structural equation modeling: Review, issues, and illustrations. Research Synthesis Methods, 7(2), 140–155. http://doi.org/10.1002/jrsm.1166
Best,
Mike
Hello Mike,
Thank you for the guidance.
I will follow the example you have sent.
Best regards,
Arin