1. Have a control/baseline/placebo group. 2. Randomize allocation to study groups. 3. Ensure double-blind trials. - Neither subjects nor experimenters should know who is in which group. 1. Measure everyone. - Even subjects that did not participate or drop out. 1. Treat all groups equally. 2. Repeat & reproduce the trial. - Increase the results' robustness. Source: The Art of Statistics by David Spiegelhalter