R help - Nov 2009 - Robust ANOVA or alternative test?

Dear Colleagues,
 
I am running a three-way mixed-design ANOVA, with one manipulated IV, a group
membership IV, and pre-/post- within subject factor. I am interested in the
three-way interaction effect. The regular ANVOA is problematic, because (a) the
sample sizes are very unbalanced, due to the group IV, (b) the homogeneity
of variance is violated, and (c) the homogeneity of covariance is also violated.
I wonder if R has a procedure to address this issue, either by some sort of
Robust ANOVA procedure, or by some alternative tests? Thanks a lot.

Jinyan Fan

Assistant Professor 
Department of Psychology 
Hofstra University 
Hempstead, NY 11550 
Work: 516-463-6349


      
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Hello

On 11/2/09, jinyan fan <fanjinyan at yahoo.com>
wrote:
> to address this issue, either by some sort of Robust ANOVA procedure, or by
some alternative tests? Thanks a lot.
>
I cannot address this specific question, but you may want to address
robustness-related queries to r-sig-robust, and perhaps check the
Robust [1] Task View.
Best
Liviu

[1] http://cran.r-project.org/web/views/Robust.html

See the nlme library and accompanying book by Pinheiro and Bates.  The
lme function is appropriate for linear mixed models with normal
errors, and the 'weights' argument provides flexible methods for
modeling error heterogeneity.

hth,
Kingsford

On Mon, Nov 2, 2009 at 12:10 PM, jinyan fan <fanjinyan at yahoo.com>
wrote:
> Dear Colleagues,
>
> I am running a three-way mixed-design ANOVA, with one manipulated IV, a
group membership IV, and pre-/post- within subject factor. I am interested in
the three-way interaction effect. The regular ANVOA is problematic, because (a)
the sample sizes are very unbalanced, due to the group IV, (b) the homogeneity
of?variance?is violated, and (c) the homogeneity of covariance is also violated.
I wonder if R has a procedure to address this issue, either by some sort of
Robust ANOVA procedure, or by some alternative tests? Thanks a lot.
>
> Jinyan Fan
>
> Assistant Professor
> Department of Psychology
> Hofstra University
> Hempstead, NY 11550
> Work: 516-463-6349
>
>
>
> ? ? ? ?[[alternative HTML version deleted]]
>
>
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