I have the following problem: how appropriate is my aov model under the
violation of anova assumptions?
Example:
a<-c(1,1,1,1,1,1,1,1,1,1,2,2,2,3,3,3,3,3,3,3)
b<-c(101,1010,200,300,400, 202, 121, 234, 55,555,66,76,88,34,239, 30, 40,
50,50,60)
z<-data.frame(a, b)
fligner.test(z$b, factor(z$a))
aov(z$b~factor(z$a))->ll
TukeyHSD(ll)
Now from the aov i found that my model is unbalanced, and from the
flinger test i found out that the assumption of homogeneity of variances
is rejected. Could my Tukey comparison be a valid one under these
violations? From what i read the Tukey test is valid only when the model
is balanced and when the assumption of homogeneity of variances is not
rejected, am i wrong? Can anyone tell me what would be the correct test in
this case?
Doing a non-parametric Kruskal - wallis test would give me a different
result. But what would be the correct multiple comparison test in this
case?