I've often worried about medical research because human trials are necessarily so small. And they're expensive to run, so there seems to be an incentive only to conduct an experiment only when it will win acclaim for the experimenter.

I wonder if medicine needs to be supplemented with things that are not clinical trials -- simulation runs or Brin-style big-but-sloppy survey-data studies. These are not a replacement for medical science, but they are at the very least a sanity check. And sanity checks are cheap and quick, so it's easier to ask researchers to do a sanity check than to spend lots of time and money replicating another clinical trial.