[R] (no subject)

[Daniel Wagenaar]

Thank you all for your helpful responses. I apologize for the lack of 
subject line. That is certainly not my habit. It happened because my 
first email was refused because it was sent using an incorrect "From:" 
line (an aliases email address, daniel.wagenaar at uc.edu) instead of the 
address I subscribed to the list with. When I resent it, I failed to 
copy the subject line. My apologies.

- Daniel

On 10/30/2015 03:12 PM, Kevin Wright wrote:
> Maybe you want
>
> summary(aov(Y ~ A + Error(A:B)))
>
> Kevin
>
>
> On Fri, Oct 30, 2015 at 9:32 AM, Wagenaar, Daniel (wagenadl)
> <wagenadl at ucmail.uc.edu <mailto:wagenadl at ucmail.uc.edu>> wrote:
>
>     Dear R users:
>
>     All textbook references that I consult say that in a nested ANOVA
>     (e.g., A/B), the F statistic for factor A should be calculated as
>     F_A = MS_A / MS_(B within A). But when I run this simple example:
>
>     set.seed(1)
>     A = factor(rep(1:3, each=4))
>     B = factor(rep(1:2, 3, each=2))
>     Y = rnorm(12)
>     anova(lm(Y ~ A/B))
>
>     I get this result:
>
>     Analysis of Variance Table
>
>     Response: Y
>                Df Sum Sq Mean Sq F value Pr(>F)
>     A          2 0.4735 0.23675  0.2845 0.7620
>     A:B        3 1.7635 0.58783  0.7064 0.5823
>     Residuals  6 4.9931 0.83218
>
>     Evidently, R calculates the F value for A as MS_A / MS_Residuals.
>     While it is straightforward enough to calculate what I think is the
>     correct result from the table, I am surprised that R doesn't give me
>     that answer directly. Does anybody know if R's behavior is
>     intentional, and if so, why? And, perhaps most importantly, how to
>     get the "textbook" result in the most straightforward way? (I'd like
>     to be able to give me students a simple procedure...)
>
>     Thanks,
>
>     Daniel Wagenaar
>
>     --
>     Daniel A. Wagenaar, PhD
>     Assistant Professor
>     Department of Biological Sciences
>     McMicken College of Arts and Sciences
>     University of Cincinnati
>     Cincinnati, OH 45221
>     Phone: +1 (513) 556-9757
>     Email: daniel.wagenaar at uc.edu <mailto:daniel.wagenaar at uc.edu>
>     Web: http://www.danielwagenaar.net
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>
>
>
> --
> Kevin Wright