Re: how to get overall F-test for GLM ANOVA analysis?

Posted by Bruce Weaver on Mar 04, 2021; 7:53pm
URL: http://spssx-discussion.165.s1.nabble.com/how-to-get-overall-F-test-for-GLM-ANOVA-analysis-tp5740241p5740251.html

Thank you for providing that additional info, Bozena.  The thing I am still
stuck on is the notion of a general F-test for the entire model in the case
of a mixed-design ANOVA.  

For a two-factor totally between-Ss ANOVA, the first partition of the SS is
into between-cells and within-cells.  And MS_between-cells / MS_within-cells
gives an F-test for the "model".  I assume the reviewer is asking for
something analogous to that.  

But in the case of a repeated measures or mixed design, the first partition
of the SS is into between-subjects and within-subjects.  In a completely
within-Ss design, the between-Ss variability is set aside and does not enter
into any of the F-tests.  But not so in the mixed design.  In both cases, I
do not see how to achieve something analogous to the overall test for the
"model" one gets for the completely between-Ss design.  I wonder if the
reviewer actually knows how to do that!  



Zdaniuk, Bozena-3 wrote

> Hello Bruce and Others,
> We conducted 5 mixed effect ANOVAS (2 within-sb factors and one btw-sb
> factor) and 4 RM ANOVAS (2 within-sb factors). The reviewer has asked that
> we control for multiple ANOVA testing by adjusting the p-values of the
> 'general F-test' for each ANOVA rather than adjusting the main effect or
> interaction effect p-values. I have searched the internet for hours and
> the only thing I found was someone on the stats.stackexchange talking
> about adjusting for multiple ANOVAS by first adjusting the 'overall
> F-tests"
> (https://stats.stackexchange.com/questions/373829/adjusting-p-values-for-multiple-anovas)
> but not explaining what they meant by that. In response to that message,
> someone further interpreted such a test as "the whole model variance
> compared to the null model variance" which sounds to me very much like the
> F-test for regression model.
> This is all I have found so far...
> Any thoughts on whether it's possible to get such 'general' F-test for
> ANOVAS? Or is the reviewer's request misguided?
> Thanks so much!
> Bozena

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Bruce Weaver
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