Re: [R] A concrete type I/III Sum of square problem

From: Gregor Gorjanc <>
Date: Thu 16 Feb 2006 - 17:37:20 EST

> WPhantom <> writes:

>>> Thanks Brian for the reference.
>>>   I just discover that it is available in our 
>>> library so I going to take it & read it soon.
>>> Actually, I don't even know the difference 
>>> between a multistratum vs a single-stratum AOV. A 
>>> quick search on google returned me the R materials so that I imagine
>>> that these concepts are quite specific to R.

> You have to be careful not to confuse Google's view of the world with
> Reality...
> The concept of error strata is much older than R, and existed for
> instance in Genstat, anno 1977 or so. However, Genstat seems to have
> left little impression on the Internet.
>>> I will read the book first before asking for more informations.

> The executive summary is that the concept of error strata relies
> substantially on having a balanced design (at least for the random
> effects), so that the analysis can be decomposed into analyses of
> means, contrasts, and contrasts of means. For unbalanced designs, you
> usually get meaningless analyses.

Can you (prof. Dalgaard) please point us to relevant book with these topics. I am very interested in it since my data are often unbalanced.

>>> Thanks
>>> Sylvain Cl?ment
>>> At 12:38 14/02/2006, you wrote:
>>>> >More to the point, you are confusing 
>>>> >multistratum AOV with single-stratuam AOV.  For 
>>>> >a good tutorial, see MASS4 (bibliographic 
>>>> >information in the R FAQ).  For unbalanced data 
>>>> >we suggest you use lme() instead.

I do not have the whole book in my head as prof. Ripley probably does, but I can not recall to read about this in MASS4. I am sure I am wrong and would you (prof. Ripley) be please so kind and point us to relevant chapters/pages.

Many thanks.

Lep pozdrav / With regards,
    Gregor Gorjanc

University of Ljubljana     PhD student
Biotechnical Faculty
Zootechnical Department     URI:
Groblje 3                   mail: gregor.gorjanc <at>

SI-1230 Domzale             tel: +386 (0)1 72 17 861
Slovenia, Europe            fax: +386 (0)1 72 17 888

"One must learn by doing the thing; for though you think you know it,
 you have no certainty until you try." Sophocles ~ 450 B.C.

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Received on Thu Feb 16 17:43:13 2006

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