R help - Jun 2007 - Post-hoc tests for interactions of between- and within-subject factors

Is there a standardized way in R to perform post-hoc comparisons for main
adn interaction effects of between- and within-subject factors?

For instance, I have a data set of performance of adults of different age
groups (20-30, 60-70,70-80) performing a WM task (n-back, with n=1,2,3,4) in
two different conditions (while sitting or walking). The corresponding ANOVA
produces the following output


> gm = aov(cog ~ agegp*nback*cond+Error(id/(cond*nback)),data = g);
> summary(gm)
Error: id
      Df Sum Sq Mean Sq
agegp  1 7.0268  7.0268

Error: id:cond
     Df Sum Sq Mean Sq
cond  1 5.1788  5.1788

Error: id:nback
      Df Sum Sq Mean Sq
nback  2 586.88  293.44

Error: id:cond:nback
           Df Sum Sq Mean Sq
nback:cond  2 2.8901  1.4451

Error: Within
                  Df Sum Sq Mean Sq F value    Pr(>F)
agegp              2 139.29   69.64 45.4349 < 2.2e-16 ***
nback              2 145.40   72.70 47.4288 < 2.2e-16 ***
cond               1   0.38    0.38  0.2495 0.6176019
agegp:nback        4  30.32    7.58  4.9448 0.0006367 ***
agegp:cond         2   1.44    0.72  0.4698 0.6254042
nback:cond         2   0.25    0.12  0.0815 0.9217123
agegp:nback:cond   4   2.22    0.56  0.3621 0.8356007
Residuals        546 836.92    1.53
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05
'.' 0.1 ' ' 1
 
 


TukeyHSD does not seem to work for within-person factors. Any suggestions
how to perform post-hoc comparions?

Thanks in advance, 
      Julius



-- 

Julius Verrel (PhD student)
MPI for Human Development
Lentzeallee 94
D-14195 Berlin
+49 30 82406-410

The glht function in package multcomp requires "aov" objects.
As you discovered, it does not work with "aovlist" objects.

See the documentation ?MMC in the HH package from CRAN.
The maiz example is similar to your example.  Come back
to the list if you need further help.

Rich