My initial approach was to attempt to use a multinomial goodness of fit test, but the data sets (A,B, and C) that I want to compare to my reference data set (D) are ALL significantly different from D. As a result, I want to at least be able to distinguish A,B, and C in HOW dissimilar they are to D.

I then tried using non-metric multi-dimensional scaling, and while this gives me a graphical representation of the kind of results I'm looking for, I'm wondering if there is a way to generate a quantitative measure of these differences.

Thanks again