I would use weighted averages, as I said above. You can play with them in different ways to get different kinds of information, but as long as we don't have any really good ways to estimate uncertainties, there is no way you'll ever get a "significance test" in the ordinary sense of the term.

I have to run now, but if you'd like, I can play around with a couple of different measures when I get home, to see what comes out.

- Jake

Friends come and go. Enemies accumulate.