sci·en·tif·ic meth·od
noun
a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.
And one more key element: peer review. Any experiment you carry out has to be able to be reproduced by other scientists, with the same results for a claim to hold merit.
Source: Quora.com