Unleashed by bias and chance

When I entered research, among the first things to be taught was that when studying the effect of an intervention, e.g. a drug, bias is masking its “true” effect; to a beginner’s eye, this was picturing bias as something bad to allow to have in an experiment and that we had to eliminate it.

Later, of course I understood that not all sort of bias is equally bad. Some can be easily identified and predicted in…