Occam's razor

Due to the possibility of confounding factors, scientific studies - no matter how well conceived and executed - don't offer us certainty about cause-effect relationships. However, uncertainty is not the same as nihilism. We tame uncertainty with our common sense. In formal terms, we keep potential confounding factors at bay with Occam's razor. If you test a causal hypothesis and the results match your prediction, maybe your hypothesis is true, or maybe it's false and the results are due to the effect of confounding factors. A study is "elegant" when the first possibility requires a simple and straightforward explanation, and the latter requires a convoluted one. Science is full of elegant studies. Science is the triumph of Occam's razor.