[R] simple main effect.

[S Devriese]

On 12/20/2009 04:56 PM, Or Duek wrote:
> I don't have missing data.
> about what I need.
> Lets say the drug*strain interaction is significant - now I want to check
> for drug under the levels of strain - compare drug 1 and 2 only on strain 1
> and then only on strain 2.
> Or I'd like to compare the strains under levels of exposure.
> This is the kind of data I fail to see in summary() but it is important to
> understand the interactions.
> thank you.
> 

Do you main pairwise multiple comparison tests like Tukey Honest
Significant Difference tests? Then you could use TukeyHSD in the stats
package or see the DTK package (Dunnett-Tukey-Kramer Pairwise Multiple
Comparison Test Adjusted for Unequal Variances and Unequal Sample Sizes)

Stephan