This technique uses the contrast between multiple samples, or observations, or populations, under differing conditions, to see what varies or what remains the same.
Təmusne tən adakal animašrayan ən gar ajotnen śolotan, meɣ ikayadan, meɣ aljamaɣatan, dǎɣ tabaraten abdanen, fal ahanay nawa abdan meɣ awa eqal iyandǎɣ.