Ring kawéntenan puniki, percobaan kakawitin antuk makarya kalih utawi lebih kelompok sampel sané ekivalen ring probabilistiknyané, punika raris indik pengukuran sifat-sifat mangda mesib pantaraning kelompok-kelompok miwah kelompok-kelompok punika mangda harus merespons dengan cara yang sama jika diberi perlakuan yang sama.
In this case, the experiment begins by creating two or more sample groups that are probabilistically equivalent, which means that measurements of traits should be similar among the groups and that the groups should respond in the same manner if given the same treatment.