ABSTRACT
Even if the mediate purpose is the disestablishment of some current idea, the immediate objective of a working scientist is likely to be to gain affirmative evidence in favor of something that will refute the allegation which is under attack. The event which has been found to have happened, in this case the small P, is to be considered as evidence in favor of any hypothesis under which it would be a frequent occurrence. Since by definition such P’s will occur frequently in the case in which the null hypothesis is true, the finding of one is to be taken as prima facie evidence in favor of the null hypothesis. If a test for the difference between means has yielded a large or middle P, it does not merely fail to disprove the null hypothesis that the true means are equal; it furnishes affirmative evidence that the means are substantially equal.
