  Hello Everyone,

*Question: *How do you calculate the sum of squares for a two-way 
_unbalanced_ ANOVA?

*What I have done:*
I have found many useful tutorials online for running a balanced two-way 
ANOVA but I haven't had much luck for running a unbalanced two-way 
ANOVA. From what I have read, the trouble with running an unbalanced 
two-way ANOVA, is that things get tricky when calculating the sum of 
squares for two factors and the interaction term.

*What I am stuck on:*
So far what I have done is applied my data to this helpful tutorial: 
http://www.biw.kuleuven.be/vakken/statisticsbyr/ANOVAbyRr/UnbalancedTwoWayANOVA.htm 

I found that my interaction term was insignificant, so my model was 
reduced to a two-factor model. But then I got stuck on the part where I 
use a general linear test (GLT) to determine whether I should use a two- 
or one- factor model to get my correct sum of squares decomposition for 
my unbalanced ANOVA. I found that there was significance between my two- 
and one- factor models (p=2.124x10^-6). But now I do not know which 
model to use for obtaining the correct sum of squares for my unbalanced 
two-way ANOVA.

I am still a novice at writing R code (~6ish months of experience) so I 
apologize if there is any error in how I delivered this message. Any 
help regarding this topic would be most appreciated. Please try to make 
any replies as simple as possible, most code in R is still new to me. 
Thanks for reading!



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