[R] lm ANOVA vs. AOV

[Peter Dalgaard]

Matthew Bridgman wrote:
> Why would someone use lm and ANOVA (anova(lm(x))) instead of AOV (or  
> the other way around)?
> The mean squares and sum of squares are the same, but the F values  
> and p-values are slightly different.
>
>   
Crudely put, aov() is effectively useless on unbalanced designs. On the 
other hand, it will allow you to handle models with multistratum error 
structure.

I am somewhat at a loss as to how you manage to get the same MS and SS 
but different F. Presumably, the denominator is different, but if you're 
not messing with Error() terms, then I believe both aov() and 
anova(lm()) would use the residual MS. An example might help.

> I am modeling a dependent~independent1*independent2.
>
> Thanks,
> Matt Bridgman
> 	[[alternative HTML version deleted]]
>
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