Re: how to analyse correlation between continuous data and classification data


to Dr. Uebersax:
At first,I appreciate you very much for yous valuable advices!
I need write in detail on my experiment because I should
cautiously treat my data .
My experiment is
I want to measure lodge of every plant of a sample .I adopted
two method to measure the lodging trait of each plant. one is to
classify to five levels,this method is classical method.Another method
is measure power of anti-breaking of stem,plant height and biomass per
plant ,then I can compute to a new variable using all of three traits
above which is called anti-lodge index .is continuous .this new method
is created by me after my consulting many literatures
Now I want to know if the Anti-lodge Index is the same to
calssical method in evaluating lodge of plant ? So I want to do
correlation of two group data which are anti-lodge index data and
classification data.
I think just to use pearson coefficient is too risky.Plase teach
me .Thank you very much!

.