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 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.