[R] CFA in R/sem package

[Iuri Gavronski]

Jarret,

Look:
> install.packages("sem.additions", repos="http://R-Forge.R-project.org")
Warning message:
package ‘sem.additions’ is not available
>

Best,

Iuri.

On Thu, Apr 9, 2009 at 3:10 PM, Jarrett Byrnes <byrnes at msi.ucsb.edu> wrote:
> Ivan,
>
> I recently put together the sem.additions package over at R forge in part
> for just such a multiple model problem.  THere are a variety of methods that
> make it easy to add/delete links that could be automated with a for loop and
> something from the combn package, I think.
>
> http://r-forge.r-project.org/projects/sem-additions/
>
> -Jarrett
>
> On Apr 9, 2009, at 6:39 AM, Iuri Gavronski wrote:
>
>> Hi,
>>
>> I am not sure if R-help is the right forum for my question. If not,
>> please let me know.
>>
>> I have to do some discriminant validity tests with some constructs. I
>> am using the method of doing a CFA constraining the correlation of a
>> pair of the constructs to 1 and comparing the chi-square of this
>> constrained model to the unconstrained model. If the chi-square
>> difference is not significant, then I cannot reject the null
>> hypothesis that the two constructs are equal.
>>
>> Well, if you are going to test, say, 4 constructs (A, B, C, and D),
>> you will have to have 2*C(4,2) = 12 models to test, 5 constructs, 20
>> models, and so forth. A tedious and error prone process...
>>
>> So far, I have been using AMOS for that shake, given that 1) my
>> university has the license, 2) my other colleagues use it, and 3) I
>> know it ;)
>>
>> I would like to know if any of you use R, namely the sem package, for
>> that application and if you can share your thoughts/experiences on
>> using it. I don't thing I would have problems "porting" my models to
>> R/sem, but I would like to know if there is an optimized process of
>> doing that tests, without manually coding all the dozens of models.
>>
>> Best,
>>
>> Iuri.
>>
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>> http://www.R-project.org/posting-guide.html
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>
> ______________________________________________
> 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.
>