Wow. Thanks everyone for your input! I just came across the following reference. In Chaudhuri's and Stenger's "Survey Sampling: Theory and Methods" they mention (Chapter 2, pp 55--57) "representative" sampling strategies. (If I can, I'll scan the few pages in and post them up somewhere so all can see). However, this book is rather hard to read and understand, so I don't know if this is the same flavor of the term "representative" that I mentioned in my original post. Specifically, the pages reference a paper by Hajek (1959) "Optimum strategy and other problems in probability sampling" (Cas. Pest. Mat. 84, 387--473) where Hajek mentions various sampling stratagies and some (statistical) conditions that "representative samples" meet. I'm having a hard time tracking down this paper, so I don't know exactly if this is what I'm looking for. Anyone heard of such conditions?