The Rules of Strong Inference:
Strong Inference is a method for looking at scientific problems by trying to disprove hypotheses and accepting the hypotheses that can not be disproved.  Using Strong Inference entails following these rules (from an article by John Platt, 1964):

1.  Devise multiple hypotheses.

2.  Design experiment(s) to eliminate one or more of the hypotheses.

3.  Carry out the experiments in a manner that gives a clean result.

4.  Repeat.  Refine hypotheses.