4 messages · Anthony Dick, John Fox
Does anyone know if the sem package in R can implement a stacked model comparison, for example as in LISREL or AMOS? Thanks, Anthony
Anthony Steven Dick, Ph.D. Post-Doctoral Fellow Human Neuroscience Laboratory Department of Neurology The University of Chicago 5841 S. Maryland Ave. MC-2030 Chicago, IL 60637 Phone: (773)-834-7770 Email: adick at uchicago.edu Web: http://home.uchicago.edu/~adick/
Dear Anthony, I'm not sure what you mean by a "stacked model comparison." If you mean a model fit to multiple groups, then the answer is no. If you mean comparison of nested models, then anova() can be used to get a LR test. See ?anova.sem. I hope this helps, John ------------------------------ John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario, Canada web: socserv.mcmaster.ca/jfox
-----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
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Behalf Of Anthony Dick Sent: January-06-09 2:56 PM To: r-help at r-project.org Subject: [R] R SEM package Does anyone know if the sem package in R can implement a stacked model comparison, for example as in LISREL or AMOS? Thanks, Anthony -- Anthony Steven Dick, Ph.D. Post-Doctoral Fellow Human Neuroscience Laboratory Department of Neurology The University of Chicago 5841 S. Maryland Ave. MC-2030 Chicago, IL 60637 Phone: (773)-834-7770 Email: adick at uchicago.edu Web: http://home.uchicago.edu/~adick/
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide
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and provide commented, minimal, self-contained, reproducible code.
Hi John- Thanks for responding so quickly. Love the package by the way. I am using R sem to model fMRI data, and I want to compare models between conditions (i.e., to see if there is a significant difference between specific path coefficients of two models). I believe this amounts to what is commonly referred to as a multi-group analysis, where two models are run simultaneously, allowing some coefficients to vary while others are maintained. The procedure is described briefly in the Appendix of: Pugesek & Tomer (1996). Evolutionary Ecology, 10, 387-404. I am not sure if anova() does what I want it to. Anthony
Dear Anthony, I'm not sure what you mean by a "stacked model comparison." If you mean a model fit to multiple groups, then the answer is no. If you mean comparison of nested models, then anova() can be used to get a LR test. See ?anova.sem. I hope this helps, John ------------------------------ John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario, Canada web: socserv.mcmaster.ca/jfox
-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On
Behalf Of Anthony Dick Sent: January-06-09 2:56 PM To: r-help at r-project.org Subject: [R] R SEM package Does anyone know if the sem package in R can implement a stacked model comparison, for example as in LISREL or AMOS? Thanks, Anthony -- Anthony Steven Dick, Ph.D. Post-Doctoral Fellow Human Neuroscience Laboratory Department of Neurology The University of Chicago 5841 S. Maryland Ave. MC-2030 Chicago, IL 60637 Phone: (773)-834-7770 Email: adick at uchicago.edu Web: http://home.uchicago.edu/~adick/
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Anthony Steven Dick, Ph.D. Post-Doctoral Fellow Human Neuroscience Laboratory Department of Neurology The University of Chicago 5841 S. Maryland Ave. MC-2030 Chicago, IL 60637 Phone: (773)-834-7770 Email: adick at uchicago.edu Web: http://home.uchicago.edu/~adick/
Dear Anthony, As I said, the sem package won't do multiple-group analysis. I would like at some point to add multiple-group analysis to the capabilities of the package but I can't say when I might find time to do that. Sorry, John ------------------------------ John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario, Canada web: socserv.mcmaster.ca/jfox
-----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
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Behalf Of Anthony Dick Sent: January-06-09 3:57 PM Cc: r-help at r-project.org Subject: Re: [R] R SEM package Hi John- Thanks for responding so quickly. Love the package by the way. I am using R sem to model fMRI data, and I want to compare models between conditions (i.e., to see if there is a significant difference between specific path coefficients of two models). I believe this amounts to what is commonly referred to as a multi-group analysis, where two models are run simultaneously, allowing some coefficients to vary while others are maintained. The procedure is described briefly in the Appendix of: Pugesek & Tomer (1996). Evolutionary Ecology, 10, 387-404. I am not sure if anova() does what I want it to. Anthony John Fox wrote:
Dear Anthony, I'm not sure what you mean by a "stacked model comparison." If you mean
a
model fit to multiple groups, then the answer is no. If you mean
comparison
of nested models, then anova() can be used to get a LR test. See
?anova.sem.
I hope this helps, John ------------------------------ John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario, Canada web: socserv.mcmaster.ca/jfox
-----Original Message----- From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org]
On
Behalf Of Anthony Dick Sent: January-06-09 2:56 PM To: r-help at r-project.org Subject: [R] R SEM package Does anyone know if the sem package in R can implement a stacked model comparison, for example as in LISREL or AMOS? Thanks, Anthony -- Anthony Steven Dick, Ph.D. Post-Doctoral Fellow Human Neuroscience Laboratory Department of Neurology The University of Chicago 5841 S. Maryland Ave. MC-2030 Chicago, IL 60637 Phone: (773)-834-7770 Email: adick at uchicago.edu Web: http://home.uchicago.edu/~adick/
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
-- Anthony Steven Dick, Ph.D. Post-Doctoral Fellow Human Neuroscience Laboratory Department of Neurology The University of Chicago 5841 S. Maryland Ave. MC-2030 Chicago, IL 60637 Phone: (773)-834-7770 Email: adick at uchicago.edu Web: http://home.uchicago.edu/~adick/
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.