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-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of Anthony Dick > Sent: January-06-09 3:57 PM > Cc: r-help@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-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > >> > > On > > > >> Behalf Of Anthony Dick > >> Sent: January-06-09 2:56 PM > >> To: r-help@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: ad...@uchicago.edu > >> Web: http://home.uchicago.edu/~adick/ > >> > >> ______________________________________________ > >> R-help@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: ad...@uchicago.edu > Web: http://home.uchicago.edu/~adick/ > > ______________________________________________ > R-help@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. ______________________________________________ R-help@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.