Abstract
Two-sample problem is discussed to detect the difference between the present and future climates. Statistical test is often encapslated in a black box in which the procedures are hidden so that it is not easy for the policymakers and the common people to comprehend it, also the researchers may not convince themselves of their conducted results by employing the abstract concept derived in mathematical sense. The test should be therefore better to be clear: the occurence number is a kind of understandable facts, while the amount of precipitation is indirect through the return period. A simple but effective method is proposed by degree of experience in extreme value analysis, and an example is demonstrated to grasp the effectiveness.