[R] correlation

[darteta001 at ikasle.ehu.es]

Dear list

I would like to compare two measurements of disease severity (M1 and 
M2), one of the is continuous (M1 ranging from 1 to 10) and the other 
is ordinal (M2 takes Low, Medium, high and very high). Do you think is 
ok to use cor() function to test whether the two agree, i.e correlate? 
I am afraid that if I set M2 to 1,2,3 and 4, the function cor() will 
take them as continuous and therefore lose intrepretation.

Thanks for your commments

David