You don't need to run an experiment to perform a valid test of one of your theories or hypotheses (whether informal or scientific). There is a technique, which I'll describe below, that can be far faster, and is used a lot less than it should be (especially when trying to test a theory in science, where it could save you an month long experiment, but also, with informal theories in daily life). I aspire to use this approach significantly more often than I do now. How to Test a Theory Without...