Check out Tabachnick & Fidell (Using Multivariate Statistics): In short, it is necessary to have more cases than DVs in every cell. In addition, power is reduced unless there are more cases than DVs in every cell because of reduced df for error.
Scott Millis
~~~~~~~~~~~
"Kunst ist schön, macht aber viel Arbeit."
Scott R Millis, PhD, ABPP (CN,CL,RP), CStat, CSci
Professor & Director of Research
Dept of Physical Medicine & Rehabilitation
Dept of Emergency Medicine
Wayne State University School of Medicine
261 Mack Blvd
Detroit, MI 48201
Email:
[hidden email]
Tel: 313-993-8085
Fax: 313-966-7682
--- On Thu, 10/8/09, Salbod, Mr. Stephen <
[hidden email]> wrote:
> From: Salbod, Mr. Stephen <
[hidden email]>
> Subject: MANOVA with small sample size and unequal ns
> To:
[hidden email]
> Date: Thursday, October 8, 2009, 7:39 AM
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> Dear Friends,
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> � � � � � � � � � � � � � � �
> I’ve
> been asked to do � one-way (3 levels) MANOVAs where the
> group sizes are n=25,
> n=7, and n=6; and, the � number of dependent variables
> can range from 6 to
> 12. � I’ve read somewhere that it is
> inappropriate to do MANOVA in
> this situation (small ns + unequal ns + large DV set
> relative to the ns). Does
> any know a reference addressing this problem?
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> � � � � � � � � � � � � � � �
> Any
> help will be greatly appreciated.
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> �
>
> Stephen Salbod, Pace University,
> NYC
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