[R] (REPOST) Simple main effects in 2-way repeated measure ANOVA

[Giuseppe Pagnoni]

Hi all

I am running a 2-way repeated measure anova with 1 between-subjects 
factor (Group=treatment, control), and 1 within-subject factor (Time of 
measurement: time1, time2).  I extract the results of the anova with:

summary(aov(effect ~ Group*Time + Error=Subj/Time, data=mydata))

Now, this must be clearly a dumb question, but how can I quickly 
extract in R all the post-hoc t-tests for the simple main effects?

Also, while I am at it, how do I enter in the model a counfounding 
covariate (e.g., Age)?

And on a different matter, is there a way to receive interactive user 
input in an R script? Something like "Enter the name of  the factor:  
", or even more simply "Press <Enter> to see the result of the next 
analysis"....

thanks in advance for any suggestions!

    giuseppe




Giuseppe Pagnoni
Dept. Psychiatry and Behavioral Sciences
Emory University
1639 Pierce Drive, Suite 4000
Atlanta, GA, 30322
tel: 404.712.8431
fax: 404.727.3233