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Re: re: st: Specifying a repeated measures analysis in anova andxtmixed


From   Joseph Coveney <jcoveney@bigplanet.com>
To   Statalist <statalist@hsphsun2.harvard.edu>
Subject   Re: re: st: Specifying a repeated measures analysis in anova andxtmixed
Date   Wed, 03 Aug 2005 01:27:19 +0900

David Airey wrote (excerpted):

At the back of Neter et al., 1996 (Applied Linear Models), there is a  
section on figuring out appropriate tests for ANOVA terms for any model

--------------------------------------------------------------------------------

Why wouldn't it just be -anova lntime case modality reader-?  The two cross-
classified random effects are assumed to be orthogonal, so there wouldn't be 
any interaction term for them, and the random effects are assumed to be 
orthogonal to the fixed effect, so there wouldn't be any interaction terms 
there, either.  It's a cross-over study design with randomized sequence (see 
documentation for Stata's -pk- suite for mention of carry-over, sequence and 
period) and not a repeated measures design, so there wouldn't be any 
-repeated()- option, to boot.  

Setting the mean squares for case and reader equal to their expected mean 
squares and solving for their sigmas will give you the variances for the two 
crossed random effects.  (Is it a listing of expected mean squares that's shown 
in the back of _Applied Linear Statistical Models_?)

Couple of corrections to my post:  I mispelled Littell, and the example of the 
crossed random effects model in the help file already has a fixed effect--the 
population mean (intercept).

Joseph Coveney

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