Сравнение на методи

	Многостепенна слоеста извадка	Стратифицирано извадково изследване
Област	Методология на проучванията	Методология на проучванията
Семейство	Process / pipeline	Process / pipeline
Година на възникване	1950s–1970s	1977
Създател	Formalized by Leslie Kish and William G. Cochran in the mid-20th century survey sampling literature	William G. Cochran
Тип	Probability sampling design	Probability-based survey sampling design
Основополагащ източник	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons. ISBN: 978-0471162407	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0-471-16240-7
Други названия	hierarchical stratified sampling, nested stratified sampling, multilevel stratified design, stratified multilevel sampling	Proportional Stratified Sampling, Optimal Allocation Sampling, Stratum-Based Sampling, Tabakalı Örnekleme
Свързани	6	2
Резюме	Multi-level stratified sampling applies stratification at two or more hierarchical levels of a nested population structure — for example, first stratifying geographic regions, then stratifying schools within each region, then stratifying classrooms within each school. This layered control over the composition of the sample at every level reduces variance and supports analysis at each level of the hierarchy, making it a powerful design for large-scale educational, epidemiological, and organizational surveys.	Stratified sampling is a probability sampling design in which the target population is partitioned into non-overlapping, exhaustive subgroups called strata, and independent probability samples are drawn within each stratum. Formalized by William G. Cochran in Sampling Techniques (1977), the method exploits known population structure to reduce variance and guarantee representativeness of all major subgroups, making it a cornerstone of large-scale survey research and official statistics.