Scientific method
Design an experiment. If the hypothesis is truly scientific, it should be possible to design an experiment to test it. An experiment should be able to tell the scientist if the hypothesis is wrong; it may not tell him or her if the hypothesis is right. As an example, think about how to show the Earth is round rather than flat. Usually scientists want to test only one thing at a time. To do this, they try to make every part of an experiment the same for everything, except for the thing they want to test.