[ghkbrew]

> Which is actually an ethical quandary when you think about it.

You're right, of course. But whether a study is scientifically valid and whether it is ethical are two orthogonal questions. Similar concerns are why most cancer therapy trials end up looking more like A/B testing than classic experimental/control experiments. The point I was trying to make, though, is that you need at least two groups which differ only by a small set of (ideally one) known variables to draw any real conclusions