Linganisha mbinu

	Utafiti wa Maelezo wa Ngazi-juu	Sampuli Iliyowekwa Ngazi
Nyanja	Muundo wa Utafiti	Metodolojia ya Dodoso
Familia	Process / pipeline	Process / pipeline
Mwaka wa asili	1980s–1990s (multilevel descriptive formalization)	1977
Mwanzilishi	Formalized within survey and educational research traditions; associated with Hox, Raudenbush, Bryk, and Creswell	William G. Cochran
Aina	Quantitative observational/descriptive design	Probability-based survey sampling design
Chanzo asilia	Hox, J. J. (2010). Multilevel Analysis: Techniques and Applications (2nd ed.). Routledge. ISBN: 978-1848728455	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0-471-16240-7
Majina mbadala	multilevel descriptive design, nested descriptive study, hierarchical survey design, stratified descriptive research	Proportional Stratified Sampling, Optimal Allocation Sampling, Stratum-Based Sampling, Tabakalı Örnekleme
Zinazohusiana	4	2
Muhtasari	Hierarchical descriptive research is an observational design that documents the current state of a phenomenon across two or more nested levels — for example, students within classrooms within schools, or employees within teams within organizations. Rather than testing hypotheses or explaining causation, it describes distributions, frequencies, and relationships at each level, making explicit the structured, layered nature of the population being studied.	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.