I have a large data set, n=2556. I have two Types, Natural (n=720), Treatment (n=1836) and 3 levels, "Not Present", >0 & <20, and >20.
What I'm trying to determine: is there a significant difference between the Types?
I determined the row frequencies, and set up a 2 x 3 contingency table.
G test 18.86, df 2, p-value 0.00008. Reject the Null hypothesis based on the p-value. (No relationship between Group type and classification level)
(I have never worked with contingency tables before, so any pointers gladly received!)
Now to the questions: Does it matter that there is such a large difference in the number of species by group?
Do I also need to determine phi?
What I'm trying to determine: is there a significant difference between the Types?
I determined the row frequencies, and set up a 2 x 3 contingency table.
G test 18.86, df 2, p-value 0.00008. Reject the Null hypothesis based on the p-value. (No relationship between Group type and classification level)
(I have never worked with contingency tables before, so any pointers gladly received!)
Now to the questions: Does it matter that there is such a large difference in the number of species by group?
Do I also need to determine phi?