Displaying 1 result from an estimated 1 matches for "watercontent".
2012 Jul 23
2
drop1, 2-way Unbalanced ANOVA
...I realize that if I just use aov() to perform a two-way ANOVA the order in
which the terms ("oxygen content" and "medium") are entered will give
different results because of the sequential SS.
What I have done in the past is utilize drop1() in conjunction with aov()
drop1(aov(WaterContent~Oxygen*Medium, data), test="F")
to see if the interaction term was significant (F, p-value) and if its
inclusion improved model fit (AIC). If from this I determine that the
interaction term can be removed and the model can be rerun without it, I am
able to test for main-effects and get F...