Experimentum crucis

In science, an experimentum crucis (English: crucial experiment or critical experiment) is an experiment capable of decisively determining whether or not a particular hypothesis or theory is superior to all other hypotheses or theories whose acceptance is currently widespread in the scientific community. In particular, such an experiment must typically be able to produce a result that rules out all other hypotheses or theories if true, thereby demonstrating that under the conditions of the experiment (i.e., under the same external circumstances and for the same "input variables" within the experiment), those hypotheses and theories are proven false but the experimenter's hypothesis is not ruled out.

An opposite view, rejecting the decisive value of the experimentum crucis in choosing one hypothesis or theory over its rivals, is the Duhem–Quine thesis; see also Pierre Duhem § Philosophy of science.