Which study is best for group/ population which is inhomogeneous?

.in STRATIFIED RANDOM SAMPLING,the sample is deliberately drawn in a systematic way so that each poion of sample represents a corresponding strata of universe.this method is paicularly useful where one is interested in analysing the data by a ceain characteristic of population.like hindus,christians,muslims,age groups etc.as we know these groupa are not equally distributed in apopulation ,that is inhomogenous.greek letters are used to refer to population charactrs while roman letters are used for sample characteristics. ref:park&;s textbook,ed 22,pg no 793