वह प्रतिचयन (Sampling) विधि जिसमें प्रारंभ में प्राकृतिक समूहों का चयन किया जाता है और फिर प्रत्येक चयनित समूह से सदस्यों का उप-प्रतिचयन किया जाता है, कहलाती है:

Which movement aimed to promote Khadi, a hand-spun and handwoven cloth native to India?

Who were prominent leaders associated with the initial phase of the Telangana Rebellion (1946-1951) against the Nizam's rule and feudal landlords?

What was the immediate trigger for the Revolt of 1857?